{"id":57,"date":"2018-10-29T09:36:06","date_gmt":"2018-10-29T09:36:06","guid":{"rendered":"http:\/\/mgmtp15.epgpbooks.inflibnet.ac.in\/?post_type=chapter&#038;p=57"},"modified":"2018-10-29T10:27:02","modified_gmt":"2018-10-29T10:27:02","slug":"measures-of-central-tendency-averages-of-positions-median-mode-quartile-deciles-percentile","status":"publish","type":"chapter","link":"https:\/\/ebooks.inflibnet.ac.in\/mgmtp15\/chapter\/measures-of-central-tendency-averages-of-positions-median-mode-quartile-deciles-percentile\/","title":{"rendered":"Measures of Central Tendency: Averages of Positions (Median, Mode, Quartile, Deciles, Percentile)"},"content":{"raw":"<div>\r\n\r\n&nbsp;\r\n\r\n<strong>Measures of Central Tendency: Averages of Positions<\/strong>\r\n\r\n&nbsp;\r\n\r\n<strong>(Median, Mode, Quartile, Deciles, Percentile)<\/strong>\r\n\r\n&nbsp;\r\n\r\n<strong>Objectives<\/strong>\r\n<ul>\r\n \t<li>After studying this module you would be able to understand:<\/li>\r\n \t<li>Concept of partition values; Median;<\/li>\r\n \t<li>Quartiles; Deciles<\/li>\r\n \t<li>Percentiles;<\/li>\r\n \t<li>Methods of calculating different partition values;<\/li>\r\n \t<li>Merits, demerits and uses of different partition values; Ogives;<\/li>\r\n \t<li>Modes;<\/li>\r\n \t<li>Methods of calculating mode; and Merits, demerits and uses of mode.<\/li>\r\n<\/ul>\r\n&nbsp;\r\n\r\n<strong>Introduction<\/strong>\r\n\r\n&nbsp;\r\n<p style=\"text-align: justify\">\u201cUttar Pradesh and Bihar's populations have the lowest median ages-or youngest populations-in India while Kerala and Tamil Nadu have the highest median ages, according to Census 2011 data, compiled by Bengaluru-based think tank Takshashila Institution.<\/p>\r\n&nbsp;\r\n<p style=\"text-align: justify\">The median age is the age which divides the population into two equal halves, i.e. there are as many people older than the median age as there are people younger than\u00a0<span style=\"font-size: 1em;text-align: initial\">it. A low median age would suggest that a country's population has more young people than older people.\u201d<\/span><\/p>\r\n\r\n<\/div>\r\n<div>\r\n\r\n&nbsp;\r\n\r\n<em>Business Standard, New Delhi September 27, 2016.<\/em>\r\n\r\n&nbsp;\r\n<p style=\"text-align: justify\">Median is a positional average which divides the data in to two equal parts when the data has been arranged either in ascending order or descending order. Similarly, there are other positional values which divide the ordered data into different number of equal parts, like, Quartiles divide in four equal parts, Deciles in ten equal parts and Percentiles in hundred equal parts.<\/p>\r\n&nbsp;\r\n\r\n<strong>A.\u00a0\u00a0 <\/strong><strong>Median<\/strong>\r\n\r\n&nbsp;\r\n<p style=\"text-align: justify\">The median is the middle value in a set of data that has been arranged from smallest to largest. Half the values are smaller than or equal to the median, and half the values are larger than or equal to the median.<\/p>\r\n&nbsp;\r\n<p style=\"text-align: justify\">As distinct from the arithmetic mean which is calculated from each and every item in the series, the median is what is called \u2018positional average\u2019. The place of the median in a series is such that an equal number of items lie on either side of it, i.e. it splits the observations into two halves. We can also say that 50% of the observations lie above median value, while rest 50% of the observations lie below median value, i.e. median lies in the middle of the series.<\/p>\r\n&nbsp;\r\n\r\n<strong>Calculation of Median \u2013 Ungrouped Data<\/strong>:\r\n\r\n&nbsp;\r\n\r\n<strong>Step-1: <\/strong>Arrange the data in ascending or descending order of magnitude.\r\n\r\n&nbsp;\r\n\r\n<strong>Step-2: Number of observation can be even or odd.<\/strong>\r\n\r\n<\/div>\r\n<div>\r\n\r\nCase-i If the number of observations is odd then median is the n 1\/2 th observation in 2 the arranged order\r\n\r\n&nbsp;\r\n\r\nSuppose a researcher wants to determine the median for the following numbers. 14, 21, 17, 22, 16, 19, 16\r\n\r\n&nbsp;\r\n\r\nThe researcher arranges the numbers in an ascending order. 14, 16, 16, 17, 19, 21, 22\r\n\r\n&nbsp;\r\n\r\n<span style=\"text-align: initial;font-size: 1em\">Since\u00a0 there\u00a0 are\u00a0 seven\u00a0 numbers,\u00a0 the\u00a0 median\u00a0 is\u00a0 the\u00a0<\/span><span style=\"text-align: initial;font-size: 1em\">7 1 \/<\/span><em style=\"text-align: initial;font-size: 1em\">th<\/em><span style=\"text-align: initial;font-size: 1em\"> 2\u00a0<\/span><span style=\"text-align: initial;font-size: 1em\">observation\u00a0 i.e.\u00a0 4th\u00a0<\/span><span style=\"font-size: 1em;text-align: initial\">observation. As 17 occur at 4th place therefore median is 17.<\/span>\r\n\r\n&nbsp;\r\n\r\n<span style=\"font-size: 1em;text-align: initial\">Case-ii If the number of observations is even then the median is the mean of n\/2 1 th observations in the arranged order<\/span>\r\n\r\n<\/div>\r\n<div>\r\n\r\nSuppose a researcher wants to determine the median for the following numbers. 14, 21, 17, 22, 16, 19, 16, 25\r\n\r\n&nbsp;\r\n\r\nThe researcher arranges the numbers in an ascending order. 14, 16, 16, 17, 19, 21, 22, 25\r\n\r\n<\/div>\r\n<div>\r\n<p style=\"text-align: justify\">Since\u00a0 there\u00a0 are\u00a0 eight\u00a0 numbers,\u00a0 the\u00a0 median\u00a0 is\u00a0 the\u00a0 mean\u00a0 of\u00a0\u00a0 <em>n<\/em>2 <em>th<\/em> and n\/2-1th\u00a0\u00a0<span style=\"font-size: 1em;text-align: initial\">observations i.e. mean of 4th and 5th observations. As 17 occur at 4th place and 19 occur at 5th place therefore median is 18.<\/span><\/p>\r\n\r\n<\/div>\r\n<div>\r\n\r\n&nbsp;\r\n\r\n<strong>Calculation of Median-Grouped Data<\/strong>:\r\n\r\n&nbsp;\r\n\r\n<span style=\"font-size: 1em;text-align: initial\">The median of grouped data can be calculated by using the following formula.<\/span>\r\n\r\n<\/div>\r\n<div>\r\n\r\n&nbsp;\r\n\r\n<img class=\"aligncenter size-full wp-image-60\" src=\"http:\/\/mgmtp15.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/81\/2018\/10\/2-18.png\" alt=\"\" width=\"216\" height=\"61\" \/>\r\n\r\nWhere l1 =lower limit of the median class\r\n\r\nl2 = upper limit of the median class\r\n\r\nm = N\/2 , N = total frequency\r\n\r\nf = frequency corresponding to the median class\r\n\r\n<span style=\"text-align: initial;text-indent: 1em;font-size: 1em\">c = cumulative frequency of the class preceding the median class.<\/span>\r\n\r\n&nbsp;\r\n<p style=\"text-align: justify\"><strong>Example 1:- <\/strong>Find the median income from the following table showing the income distribution of persons in a particular region.<\/p>\r\n&nbsp;\r\n<table class=\"aligncenter\" style=\"width: 60%\" border=\"1\">\r\n<tbody>\r\n<tr>\r\n<td><strong>Income in Rs\u00a0(in \u2019000)<\/strong><\/td>\r\n<td><strong>No. Of persons\u00a0(in hundreds)<\/strong><\/td>\r\n<\/tr>\r\n<tr>\r\n<td>Below 10<\/td>\r\n<td>2<\/td>\r\n<\/tr>\r\n<tr>\r\n<td>Below 20<\/td>\r\n<td>5<\/td>\r\n<\/tr>\r\n<tr>\r\n<td>Below 30<\/td>\r\n<td>9<\/td>\r\n<\/tr>\r\n<tr>\r\n<td>Below 40<\/td>\r\n<td>12<\/td>\r\n<\/tr>\r\n<tr>\r\n<td>Below 50<\/td>\r\n<td>14<\/td>\r\n<\/tr>\r\n<tr>\r\n<td>Below 60<\/td>\r\n<td>15<\/td>\r\n<\/tr>\r\n<tr>\r\n<td>Below 70<\/td>\r\n<td>15.5<\/td>\r\n<\/tr>\r\n<tr>\r\n<td>70 and over<\/td>\r\n<td>15.6<\/td>\r\n<\/tr>\r\n<\/tbody>\r\n<\/table>\r\n&nbsp;\r\n\r\n&nbsp;\r\n\r\n<strong>Solution<\/strong>\r\n\r\n&nbsp;\r\n<p style=\"text-align: justify\">First of all we make the classes continuous and calculate the frequencies &amp; cumulative frequencies for different classes.<\/p>\r\n\r\n<\/div>\r\n<div>\r\n<table class=\"aligncenter\" style=\"width: 60%\" border=\"1\">\r\n<tbody>\r\n<tr>\r\n<td><strong>Income in Rs<\/strong><\/td>\r\n<td><strong>No. Of persons<\/strong><\/td>\r\n<td><strong>Cumulative Frequency<\/strong><\/td>\r\n<\/tr>\r\n<tr>\r\n<td><strong>(in \u2019000)<\/strong><\/td>\r\n<td><strong>(in hundreds)<\/strong><\/td>\r\n<td><strong>(less than type)<\/strong><\/td>\r\n<\/tr>\r\n<tr>\r\n<td>0-10<\/td>\r\n<td>2<\/td>\r\n<td>2<\/td>\r\n<\/tr>\r\n<tr>\r\n<td>10-20<\/td>\r\n<td>3<\/td>\r\n<td>5<\/td>\r\n<\/tr>\r\n<tr>\r\n<td>20-30<\/td>\r\n<td>4<\/td>\r\n<td>9<\/td>\r\n<\/tr>\r\n<tr>\r\n<td>30-40<\/td>\r\n<td>3<\/td>\r\n<td>12<\/td>\r\n<\/tr>\r\n<tr>\r\n<td>40-50<\/td>\r\n<td>2<\/td>\r\n<td>14<\/td>\r\n<\/tr>\r\n<tr>\r\n<td>50-60<\/td>\r\n<td>1<\/td>\r\n<td>15<\/td>\r\n<\/tr>\r\n<tr>\r\n<td>60-70<\/td>\r\n<td>0.5<\/td>\r\n<td>15.5<\/td>\r\n<\/tr>\r\n<tr>\r\n<td>70 and over<\/td>\r\n<td>0.1<\/td>\r\n<td>15.6<\/td>\r\n<\/tr>\r\n<tr>\r\n<td><\/td>\r\n<td>N= \u2211<em>f<\/em> =15.6<\/td>\r\n<td><\/td>\r\n<\/tr>\r\n<\/tbody>\r\n<\/table>\r\n<\/div>\r\n&nbsp;\r\n\r\n<span style=\"text-align: initial;font-size: 1em\">Now, m =<\/span><em style=\"text-align: initial;font-size: 1em\">N\/2=15.6\/2=7.8<\/em>\r\n<div><\/div>\r\n<div><span style=\"text-align: initial;font-size: 1em\">Cumulative frequency (c.<\/span><em style=\"text-align: initial;font-size: 1em\">f<\/em><span style=\"text-align: initial;font-size: 1em\">.) greater than 7.8 is 9. Therefore, the median class is 20-30.<\/span><\/div>\r\n<div><\/div>\r\n<div><span style=\"text-align: initial;font-size: 1em\">L1 = 20, L2 = 30, c = 5, f = 4 and L2 - L1 = 10 .<\/span><\/div>\r\n<div>\r\n\r\n&nbsp;\r\n\r\nNow putting these values in the median formula we get\r\n\r\nMedian = 20+104 (7.8-5) = 20+ 52 x 2.8\r\n\r\n=\u00a0\u00a0 20+5 x 1.4 = 27 Hence, median income is Rs 27,000.\r\n\r\n&nbsp;\r\n\r\n<strong>Important mathematical property of median:<\/strong>\r\n\r\n&nbsp;\r\n\r\nThe sum of the deviations of the items from median, ignoring signs is the least.\r\n\r\n&nbsp;\r\n\r\n<em>n<\/em>\r\n\r\ni.e\u00a0\u00a0\u00a0 <em>\u00a0x<\/em><em>i<\/em><em>\u00a0\u00a0\u00a0\u00a0\u00a0 md <\/em>\u00a0is least.\r\n\r\n<em>i<\/em>1\r\n\r\n&nbsp;\r\n\r\n&nbsp;\r\n\r\n<strong>Merits of Median:<\/strong>\r\n\r\n&nbsp;\r\n\r\nThe median can be used in case of frequency distribution with open-end classes.\r\n\r\n&nbsp;\r\n\r\n<span style=\"font-size: 1em;text-align: initial\">The median is not affected by extreme observations.<\/span>\r\n\r\n&nbsp;\r\n\r\n<span style=\"text-align: initial;font-size: 1em\">The value of median can be determined graphically where as the value of mean cannot be determined graphically.<\/span>\r\n\r\n&nbsp;\r\n\r\n<span style=\"text-align: initial;font-size: 1em\">It is easy to calculate and understand.<\/span>\r\n\r\n<\/div>\r\n<div>\r\n\r\n&nbsp;\r\n\r\n<strong>Demerits of Median:<\/strong>\r\n\r\n&nbsp;\r\n<p style=\"text-align: justify\">For calculating median it is necessary to arrange the data in some order, ascending or descending, where as other averages do not need arrangement.<\/p>\r\n&nbsp;\r\n\r\nSince it is a positional average its value is not determined by all the observations in the series.\r\n\r\n&nbsp;\r\n\r\nMedian is not capable for further algebraic calculations.\r\n\r\n&nbsp;\r\n\r\nThe sampling stability of the median is less as compared to mean.\r\n\r\n&nbsp;\r\n\r\n<strong>B.\u00a0\u00a0 <\/strong><strong>Quartiles:<\/strong>\r\n\r\n&nbsp;\r\n<p style=\"text-align: justify\">There are three quartiles, <em>i.e.<\/em> Q1, Q2 and Q3 which divide the total data into four equal parts when it has been orderly arranged. Q1, Q2 and Q3 are termed as first quartile, second quartile and third quartile or lower quartile, middle quartile and upper quartile, respectively.<\/p>\r\n&nbsp;\r\n<p style=\"text-align: justify\">The first quartile, Q1, separates the first one-fourth of the data from the upper three-fourths and is equal to the 25th percentile. The second quartile, Q2, divides the data into two equal parts (like median) and is equal to the 50th percentile. The third quartile, Q3, separates the first three-quarters of the data from the last quarter and is equal to 75th percentile.<\/p>\r\n&nbsp;\r\n\r\n<strong>Calculation of Quartiles:<\/strong>\r\n\r\n&nbsp;\r\n\r\nThe calculation of quartiles is done exactly in the same manner as it is in case of the\u00a0<span style=\"font-size: 1em;text-align: initial\">calculation of median.<\/span>\r\n\r\n<\/div>\r\n<div>\r\n\r\n&nbsp;\r\n\r\nThe different quartiles can be found using the formula given below:\r\n\r\n<\/div>\r\n<div>\r\n\r\n&nbsp;\r\n\r\nWhere,\r\n\r\n<\/div>\r\n<div>\r\n\r\n<img class=\"aligncenter size-full wp-image-61\" src=\"http:\/\/mgmtp15.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/81\/2018\/10\/2-19.png\" alt=\"\" width=\"323\" height=\"75\" \/>\r\n\r\nl1=\u00a0 lower limit of ith quartile class\r\n\r\n&nbsp;\r\n\r\nl2=\u00a0\u00a0 upper limit of ith quartile class\r\n\r\n&nbsp;\r\n\r\n<em style=\"text-align: initial;font-size: 1em\">c <\/em><span style=\"text-align: initial;font-size: 1em\">= cumulative frequency of the class preceding the ith quartile class<\/span>\r\n\r\n&nbsp;\r\n\r\n<em style=\"text-align: initial;font-size: 1em\">f <\/em><span style=\"text-align: initial;font-size: 1em\">= frequency of ith quartile class.<\/span>\r\n\r\n<\/div>\r\n<div>\r\n\r\n&nbsp;\r\n\r\n<strong>C.\u00a0 <\/strong><strong>Deciles<\/strong>\r\n\r\n&nbsp;\r\n\r\nDeciles are the partition values which divide the arranged data into ten equal parts.\r\n\r\n&nbsp;\r\n\r\nThere are nine deciles <em>i.e.<\/em> D1, D2, D3\u2026\u2026..\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 D9\u00a0 and 5th\u00a0 decile is same as median or\r\n\r\n&nbsp;\r\n\r\nQ2, because it divides the data in two equal parts.\r\n\r\n&nbsp;\r\n\r\n<strong>Calculation of Deciles<\/strong>:\r\n\r\n&nbsp;\r\n\r\nThe calculation of deciles is done exactly in the same manner as it is in case of calculation of median.\r\n\r\n&nbsp;\r\n\r\nThe different deciles can be found using the formula given below:\r\n\r\n<img class=\"aligncenter size-full wp-image-62\" src=\"http:\/\/mgmtp15.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/81\/2018\/10\/2-20.png\" alt=\"\" width=\"388\" height=\"81\" \/>\r\n\r\n&nbsp;\r\n\r\nWhere,\r\n\r\n&nbsp;\r\n\r\n<span style=\"font-size: 1em;text-align: initial\">l1=\u00a0 lower limit of ith decile class<\/span>\r\n\r\n<span style=\"text-align: initial;font-size: 1em\">l2=\u00a0 upper limit of ith decile class<\/span>\r\n\r\n<em style=\"text-align: initial;font-size: 1em\">c <\/em><span style=\"text-align: initial;font-size: 1em\">= cumulative frequency of the class preceding the ith decile class<\/span>\r\n\r\n<em style=\"text-align: initial;font-size: 1em\">f <\/em><span style=\"text-align: initial;font-size: 1em\">= frequency of ith decile class.<\/span>\r\n\r\n<\/div>\r\n<div>\r\n\r\n&nbsp;\r\n\r\n<strong>D. Percentiles<\/strong>\r\n\r\n&nbsp;\r\n<p style=\"text-align: justify\">Percentiles are the values which divide the arranged data into hundred equal parts. There are 99 percentiles <em>i.e.<\/em> P1, P2, P3, \u2026\u2026..,P99. The 50th percentile divides the series into two equal parts and P50 = D5 = Median.<\/p>\r\n&nbsp;\r\n\r\nSimilarly the value of Q1 = P25 and value of Q3 = P75\r\n\r\n&nbsp;\r\n\r\n<strong>Calculation of Percentiles:<\/strong>\r\n\r\n&nbsp;\r\n\r\nThe different percentiles can be found using the formula given below:\r\n\r\n<\/div>\r\n<div>\r\n\r\n<img class=\"aligncenter size-full wp-image-63\" src=\"http:\/\/mgmtp15.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/81\/2018\/10\/2-21.png\" alt=\"\" width=\"419\" height=\"88\" \/>\r\n\r\nWhere,\r\n\r\n<\/div>\r\n<div>\r\n\r\nl1=\u00a0 lower limit of ith percentile class\r\n\r\nl2=\u00a0 upper limit of ith percentile class\r\n\r\n<em style=\"text-align: initial;font-size: 1em\">c <\/em><span style=\"text-align: initial;font-size: 1em\">= cumulative frequency of the class preceding the ith percentile class<\/span>\r\n\r\n<em style=\"text-align: initial;font-size: 1em\">f <\/em><span style=\"text-align: initial;font-size: 1em\">= frequency of ith percentile class.<\/span>\r\n\r\n<\/div>\r\n<strong style=\"text-align: initial;font-size: 1em\">Merits of Quartiles, Deciles and Percentiles:<\/strong>\r\n<div>\r\n\r\n&nbsp;\r\n\r\nThese positional values can be directly determined in case of open end class intervals.\r\n\r\n&nbsp;\r\n<p style=\"text-align: justify\">These positional values can be calculated easily in absence of some data. These are helpful in the calculation of measures of skewness.<\/p>\r\n&nbsp;\r\n\r\nThese are not affected very much by the extreme items. These can be located graphically.\r\n\r\n&nbsp;\r\n\r\n<strong>Demerits of Quartiles, Deciles and Percentiles:<\/strong>\r\n\r\n&nbsp;\r\n\r\nThese values are not easily understood by a common man.\r\n\r\n&nbsp;\r\n\r\nThese values are not based on all the observations of a series.\r\n\r\n&nbsp;\r\n\r\nThese values cannot be computed if items are not given in ascending or descending order.\r\n\r\n&nbsp;\r\n\r\nThese values have less sampling stability.\r\n\r\n&nbsp;\r\n\r\n<strong>E. <\/strong><strong>Ogives<\/strong>\r\n\r\n&nbsp;\r\n\r\nAn Ogive is a way to graph information showing cumulative frequencies. It shows how many of values of the data are below certain boundary.\r\n\r\n&nbsp;\r\n<p style=\"text-align: justify\"><strong>Construction of an Ogive: <\/strong>To make an ogive, first a cumulative-frequency table is constructed. Vertical scale (y-axis) on the graph represents cumulative frequencies and horizontal scale (x-axis) represents variable of interest.<\/p>\r\n&nbsp;\r\n<p style=\"text-align: justify\"><strong>Less than type Ogive curve: <\/strong>If we start from the upper limit of class intervals and then add class frequencies to get cumulative frequency. Then such a distribution is less than type cumulative frequency distribution and plotting it on graph gives a less than type ogive curve. The less than type ogive looks like an elongated 'S'.<\/p>\r\n&nbsp;\r\n<p style=\"text-align: justify\"><strong style=\"text-align: initial;font-size: 1em\">More than type Ogive curve: <\/strong><span style=\"text-align: initial;font-size: 1em\">If we start from the lower limits of class intervals and then subtract class frequencies from the cumulative frequency. Then such a distribution is more than type cumulative frequency distribution and plotting it on graph gives a more than type ogive curve. More than type ogive looks like an elongated 'S' turned upside down.<\/span><\/p>\r\n\r\n<\/div>\r\n<div>\r\n\r\n&nbsp;\r\n\r\n<strong>Determining the Median graphically<\/strong>\r\n\r\n&nbsp;\r\n\r\nMedian can also be determined graphically by using ogives through two methods given below.\r\n\r\n&nbsp;\r\n\r\n<strong>Method-1:<\/strong>\r\n\r\n&nbsp;\r\n\r\nStep-1: Draw two ogives- one by less than method and other by more than method.\r\n\r\n&nbsp;\r\n\r\nStep-2: From the point where both these curves intersect each other draw a perpendicular on the X-axis.\r\n\r\n&nbsp;\r\n\r\nStep -3: The point where this perpendicular touches the X-axis gives the value of median.\r\n\r\n&nbsp;\r\n\r\n<strong>Method-2:<\/strong>\r\n\r\n&nbsp;\r\n\r\nStep-1: Draw only one ogive by less than method or more than method by taking variable on the X-axis and cumulative frequency on the Y-axis.\r\n\r\n<\/div>\r\n<div>\r\n\r\n&nbsp;\r\n\r\nStep-2: Determine the value of N\/2.\r\n\r\n<\/div>\r\n<div>\r\n\r\n&nbsp;\r\n\r\nStep-3: Locate this value on the Y-axis and from it draw a line parallel to X-axis which meets the ogive\r\n\r\n<\/div>\r\n&nbsp;\r\n\r\n<span style=\"text-align: initial;font-size: 1em\">Step -4: The point where this parallel line touches the ogive from it drop a perpendicular on X-axis. This point on X-axis gives the value of median.<\/span>\r\n<div>\r\n\r\n&nbsp;\r\n\r\nSimilarly, the other partition values like quartiles, deciles, etc can be also determined graphically.\r\n\r\n&nbsp;\r\n\r\n<strong>F.\u00a0\u00a0 <\/strong><strong>Mode<\/strong>\r\n\r\n&nbsp;\r\n\r\n&nbsp;\r\n<p style=\"text-align: justify\">The value of variable which occurs most frequently in data is called Mode. The concept of mode is often used in determining sizes. As an example, the most common shoe size is 6 or the most common shirt size is 42. It is a very appropriate measure of central tendency for nominal data.<\/p>\r\n&nbsp;\r\n\r\n<strong>Calculation of Mode - Ungrouped Data:<\/strong>\r\n\r\n&nbsp;\r\n\r\nIn this case mode is obtained by inspection.\r\n\r\n&nbsp;\r\n\r\n<strong>Example 2:- <\/strong>The blood pressure of 9 patients is as follows:\r\n\r\n&nbsp;\r\n\r\n86, 87, 80, 86, 76, 86, 90, 88, 86.\r\n\r\n&nbsp;\r\n\r\nCalculate its mode.\r\n\r\n&nbsp;\r\n\r\n<strong>Solution<\/strong>\r\n\r\n&nbsp;\r\n\r\nThe mode value is 86, as it occurs maximum times (i.e.4 times).\r\n\r\n&nbsp;\r\n\r\n<strong>Note: <\/strong>In certain cases there may not be a mode or there may be more than one mode.\r\n\r\n<\/div>\r\nExample 3:\r\n\r\n&nbsp;\r\n<div>a) 40, 44,57,78,84 (no mode)\r\nb) 3, 4, 5, 5, 4, 2, 1 (modes 4 and 5)\r\nc) 8, 8, 8, 8, 8 (no mode)<\/div>\r\n&nbsp;\r\n<p style=\"text-align: justify\"><span style=\"text-align: initial;font-size: 1em\">A series of data, having one mode is called \u2018unimodal\u2019 and a series of data having two modes is called \u2018bimodal\u2019. It may also have several modes and be called \u2018multimodal\u2019.<\/span><\/p>\r\n\r\n<div>\r\n\r\n&nbsp;\r\n\r\n<strong>Calculation of Mode \u2013 Grouped Data<\/strong>:\r\n\r\n&nbsp;\r\n<p style=\"text-align: justify\">In case of grouped data, modal class is determined by inspection or by preparing grouping and analysis tables. Then we apply the following formula.<\/p>\r\n&nbsp;\r\n\r\n<img class=\"aligncenter size-full wp-image-64\" src=\"http:\/\/mgmtp15.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/81\/2018\/10\/2-22.png\" alt=\"\" width=\"518\" height=\"81\" \/>\r\n\r\n<em>f <\/em>0 =frequency of the class preceding the modal class.\r\n\r\n&nbsp;\r\n\r\n<em>f <\/em>2 = frequency of the class succeeding the modal class.\r\n\r\n&nbsp;\r\n\r\n<em>i <\/em>= size of the class.\r\n\r\n&nbsp;\r\n\r\n<em style=\"text-align: initial;font-size: 1em\">f<\/em><span style=\"text-align: initial;font-size: 1em\">1 =frequency of the modal class<\/span>\r\n\r\n&nbsp;\r\n\r\n<span style=\"font-size: 1em\">l1 = lower limit of the modal class.<\/span>\r\n\r\n<\/div>\r\n<div>\r\n\r\n&nbsp;\r\n\r\n<strong>Note:<\/strong>\r\n\r\n&nbsp;\r\n<p style=\"text-align: justify\">1)\u00a0\u00a0\u00a0 While applying the above formula for calculating mode, it is necessary to see that the class intervals are uniform throughout. If they are unequal they should first be made equal on the assumption that the frequencies are equally distributed throughout.<\/p>\r\n&nbsp;\r\n\r\n2)\u00a0\u00a0\u00a0 In case of bimodal distribution the mode can\u2019t be found.\r\n\r\n&nbsp;\r\n\r\n<strong style=\"text-align: justify;font-size: 1em\">Finding mode in case of bimodal distribution: <\/strong><span style=\"text-align: justify;font-size: 1em\">In a bimodal distribution the value of mode can not be determined by the help of the above formulae. In this case the mode can be determined by using the empirical relation given below.<\/span>\r\n\r\n<\/div>\r\n<div>\r\n\r\n&nbsp;\r\n\r\n<strong>Mode = 3Median - 2Mean<\/strong>\r\n\r\n&nbsp;\r\n\r\nAnd the mode which is obtained by using the above relation is called <strong>\u2018Empirical<\/strong> <strong>mode\u2019<\/strong>\r\n\r\n&nbsp;\r\n\r\n<strong>Merits of Mode:<\/strong>\r\n\r\n&nbsp;\r\n\r\nIt is easy to calculate and simple to understand. It is not affected by the extreme values.\r\n\r\n&nbsp;\r\n\r\nThe value of mode can be determined graphically.\r\n\r\n&nbsp;\r\n\r\nIts value can be determined in case of open-end class interval.\r\n\r\n&nbsp;\r\n\r\n<strong>Demerits of Mode<\/strong>:\r\n\r\n&nbsp;\r\n\r\nIt is not suitable for further mathematical treatments. The value of mode cannot always be determined.\r\n\r\n&nbsp;\r\n\r\nThe value of mode is not based on each and every item of the series. The mode is not rigidly defined.\r\n\r\n&nbsp;\r\n\r\n<strong>Summary<\/strong>\r\n\r\n&nbsp;\r\n<p style=\"text-align: justify\">Partition values divide the data, when arranged in either ascending order or descending order, into different number of equal parts. Median is the middle value in a set of arranged data. The place of the median in a series is such that an equal number of items lie on either side of it, i.e. it splits the\u00a0<span style=\"text-align: initial;font-size: 1em\">observations into two halves. We can also say that 50% of the observations lie above median value, while rest 50% of the observations lie below median value. Quartiles divide the total data into four equal parts when it has been orderly arranged. The first quartile, Q1, separates the first one-fourth of the data from the upper three-fourths and is equal to the 25th percentile. The second quartile, Q2, divides the data into two equal parts (like median) and is equal to the 50th percentile. The third quartile, Q3, separates the first three-quarters of the data from the last quarter and is equal to 75th percentile. Deciles are the partition values which divide the arranged data into ten equal parts whereas percentiles divide the data into hundred equal parts. Ogives are cumulative frequency graphs which help in finding different partition values graphically.<\/span><\/p>\r\n\r\n<\/div>\r\n&nbsp;\r\n<p style=\"text-align: justify\">Mode is the value of variable which occurs most frequently in data. The concept of mode is often used in determining sizes. It is a very appropriate measure of central tendency for nominal data.<\/p>\r\n&nbsp;\r\n<p style=\"text-align: center\"><strong>Learn More:<\/strong><\/p>\r\n\r\n<ol>\r\n \t<li><em>Business Research Methods\u2019 Authored by Naval Bajpai, Published by Pearson\u2019s India PHI<\/em><\/li>\r\n \t<li><em>Business Statistics Authored by Dr. K.L. Gupta, Published by Nirupam Publications.<\/em><\/li>\r\n \t<li><em>Business Statistics Authored by G.C. Beri, Published by TMH Publications.<\/em><\/li>\r\n \t<li><em style=\"text-align: initial;font-size: 1em\">Statistics For Managers using Microsoft Excel by David M. Levine David F. Stephan Timothy C. Krehbiel Mark L. Berenson, Published by PEARSON<\/em><\/li>\r\n \t<li><em style=\"text-align: initial;font-size: 1em\">Business Statistics by Ken Black, Published by John Wiley &amp; Sons, Inc<\/em><\/li>\r\n<\/ol>","rendered":"<div>\n<p>&nbsp;<\/p>\n<p><strong>Measures of Central Tendency: Averages of Positions<\/strong><\/p>\n<p>&nbsp;<\/p>\n<p><strong>(Median, Mode, Quartile, Deciles, Percentile)<\/strong><\/p>\n<p>&nbsp;<\/p>\n<p><strong>Objectives<\/strong><\/p>\n<ul>\n<li>After studying this module you would be able to understand:<\/li>\n<li>Concept of partition values; Median;<\/li>\n<li>Quartiles; Deciles<\/li>\n<li>Percentiles;<\/li>\n<li>Methods of calculating different partition values;<\/li>\n<li>Merits, demerits and uses of different partition values; Ogives;<\/li>\n<li>Modes;<\/li>\n<li>Methods of calculating mode; and Merits, demerits and uses of mode.<\/li>\n<\/ul>\n<p>&nbsp;<\/p>\n<p><strong>Introduction<\/strong><\/p>\n<p>&nbsp;<\/p>\n<p style=\"text-align: justify\">\u201cUttar Pradesh and Bihar&#8217;s populations have the lowest median ages-or youngest populations-in India while Kerala and Tamil Nadu have the highest median ages, according to Census 2011 data, compiled by Bengaluru-based think tank Takshashila Institution.<\/p>\n<p>&nbsp;<\/p>\n<p style=\"text-align: justify\">The median age is the age which divides the population into two equal halves, i.e. there are as many people older than the median age as there are people younger than\u00a0<span style=\"font-size: 1em;text-align: initial\">it. A low median age would suggest that a country&#8217;s population has more young people than older people.\u201d<\/span><\/p>\n<\/div>\n<div>\n<p>&nbsp;<\/p>\n<p><em>Business Standard, New Delhi September 27, 2016.<\/em><\/p>\n<p>&nbsp;<\/p>\n<p style=\"text-align: justify\">Median is a positional average which divides the data in to two equal parts when the data has been arranged either in ascending order or descending order. Similarly, there are other positional values which divide the ordered data into different number of equal parts, like, Quartiles divide in four equal parts, Deciles in ten equal parts and Percentiles in hundred equal parts.<\/p>\n<p>&nbsp;<\/p>\n<p><strong>A.\u00a0\u00a0 <\/strong><strong>Median<\/strong><\/p>\n<p>&nbsp;<\/p>\n<p style=\"text-align: justify\">The median is the middle value in a set of data that has been arranged from smallest to largest. Half the values are smaller than or equal to the median, and half the values are larger than or equal to the median.<\/p>\n<p>&nbsp;<\/p>\n<p style=\"text-align: justify\">As distinct from the arithmetic mean which is calculated from each and every item in the series, the median is what is called \u2018positional average\u2019. The place of the median in a series is such that an equal number of items lie on either side of it, i.e. it splits the observations into two halves. We can also say that 50% of the observations lie above median value, while rest 50% of the observations lie below median value, i.e. median lies in the middle of the series.<\/p>\n<p>&nbsp;<\/p>\n<p><strong>Calculation of Median \u2013 Ungrouped Data<\/strong>:<\/p>\n<p>&nbsp;<\/p>\n<p><strong>Step-1: <\/strong>Arrange the data in ascending or descending order of magnitude.<\/p>\n<p>&nbsp;<\/p>\n<p><strong>Step-2: Number of observation can be even or odd.<\/strong><\/p>\n<\/div>\n<div>\n<p>Case-i If the number of observations is odd then median is the n 1\/2 th observation in 2 the arranged order<\/p>\n<p>&nbsp;<\/p>\n<p>Suppose a researcher wants to determine the median for the following numbers. 14, 21, 17, 22, 16, 19, 16<\/p>\n<p>&nbsp;<\/p>\n<p>The researcher arranges the numbers in an ascending order. 14, 16, 16, 17, 19, 21, 22<\/p>\n<p>&nbsp;<\/p>\n<p><span style=\"text-align: initial;font-size: 1em\">Since\u00a0 there\u00a0 are\u00a0 seven\u00a0 numbers,\u00a0 the\u00a0 median\u00a0 is\u00a0 the\u00a0<\/span><span style=\"text-align: initial;font-size: 1em\">7 1 \/<\/span><em style=\"text-align: initial;font-size: 1em\">th<\/em><span style=\"text-align: initial;font-size: 1em\"> 2\u00a0<\/span><span style=\"text-align: initial;font-size: 1em\">observation\u00a0 i.e.\u00a0 4th\u00a0<\/span><span style=\"font-size: 1em;text-align: initial\">observation. As 17 occur at 4th place therefore median is 17.<\/span><\/p>\n<p>&nbsp;<\/p>\n<p><span style=\"font-size: 1em;text-align: initial\">Case-ii If the number of observations is even then the median is the mean of n\/2 1 th observations in the arranged order<\/span><\/p>\n<\/div>\n<div>\n<p>Suppose a researcher wants to determine the median for the following numbers. 14, 21, 17, 22, 16, 19, 16, 25<\/p>\n<p>&nbsp;<\/p>\n<p>The researcher arranges the numbers in an ascending order. 14, 16, 16, 17, 19, 21, 22, 25<\/p>\n<\/div>\n<div>\n<p style=\"text-align: justify\">Since\u00a0 there\u00a0 are\u00a0 eight\u00a0 numbers,\u00a0 the\u00a0 median\u00a0 is\u00a0 the\u00a0 mean\u00a0 of\u00a0\u00a0 <em>n<\/em>2 <em>th<\/em> and n\/2-1th\u00a0\u00a0<span style=\"font-size: 1em;text-align: initial\">observations i.e. mean of 4th and 5th observations. As 17 occur at 4th place and 19 occur at 5th place therefore median is 18.<\/span><\/p>\n<\/div>\n<div>\n<p>&nbsp;<\/p>\n<p><strong>Calculation of Median-Grouped Data<\/strong>:<\/p>\n<p>&nbsp;<\/p>\n<p><span style=\"font-size: 1em;text-align: initial\">The median of grouped data can be calculated by using the following formula.<\/span><\/p>\n<\/div>\n<div>\n<p>&nbsp;<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-60\" src=\"http:\/\/mgmtp15.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/81\/2018\/10\/2-18.png\" alt=\"\" width=\"216\" height=\"61\" srcset=\"https:\/\/ebooks.inflibnet.ac.in\/mgmtp15\/wp-content\/uploads\/sites\/81\/2018\/10\/2-18.png 216w, https:\/\/ebooks.inflibnet.ac.in\/mgmtp15\/wp-content\/uploads\/sites\/81\/2018\/10\/2-18-65x18.png 65w\" sizes=\"auto, (max-width: 216px) 100vw, 216px\" \/><\/p>\n<p>Where l1 =lower limit of the median class<\/p>\n<p>l2 = upper limit of the median class<\/p>\n<p>m = N\/2 , N = total frequency<\/p>\n<p>f = frequency corresponding to the median class<\/p>\n<p><span style=\"text-align: initial;text-indent: 1em;font-size: 1em\">c = cumulative frequency of the class preceding the median class.<\/span><\/p>\n<p>&nbsp;<\/p>\n<p style=\"text-align: justify\"><strong>Example 1:- <\/strong>Find the median income from the following table showing the income distribution of persons in a particular region.<\/p>\n<p>&nbsp;<\/p>\n<table class=\"aligncenter\" style=\"width: 60%\">\n<tbody>\n<tr>\n<td><strong>Income in Rs\u00a0(in \u2019000)<\/strong><\/td>\n<td><strong>No. Of persons\u00a0(in hundreds)<\/strong><\/td>\n<\/tr>\n<tr>\n<td>Below 10<\/td>\n<td>2<\/td>\n<\/tr>\n<tr>\n<td>Below 20<\/td>\n<td>5<\/td>\n<\/tr>\n<tr>\n<td>Below 30<\/td>\n<td>9<\/td>\n<\/tr>\n<tr>\n<td>Below 40<\/td>\n<td>12<\/td>\n<\/tr>\n<tr>\n<td>Below 50<\/td>\n<td>14<\/td>\n<\/tr>\n<tr>\n<td>Below 60<\/td>\n<td>15<\/td>\n<\/tr>\n<tr>\n<td>Below 70<\/td>\n<td>15.5<\/td>\n<\/tr>\n<tr>\n<td>70 and over<\/td>\n<td>15.6<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p><strong>Solution<\/strong><\/p>\n<p>&nbsp;<\/p>\n<p style=\"text-align: justify\">First of all we make the classes continuous and calculate the frequencies &amp; cumulative frequencies for different classes.<\/p>\n<\/div>\n<div>\n<table class=\"aligncenter\" style=\"width: 60%\">\n<tbody>\n<tr>\n<td><strong>Income in Rs<\/strong><\/td>\n<td><strong>No. Of persons<\/strong><\/td>\n<td><strong>Cumulative Frequency<\/strong><\/td>\n<\/tr>\n<tr>\n<td><strong>(in \u2019000)<\/strong><\/td>\n<td><strong>(in hundreds)<\/strong><\/td>\n<td><strong>(less than type)<\/strong><\/td>\n<\/tr>\n<tr>\n<td>0-10<\/td>\n<td>2<\/td>\n<td>2<\/td>\n<\/tr>\n<tr>\n<td>10-20<\/td>\n<td>3<\/td>\n<td>5<\/td>\n<\/tr>\n<tr>\n<td>20-30<\/td>\n<td>4<\/td>\n<td>9<\/td>\n<\/tr>\n<tr>\n<td>30-40<\/td>\n<td>3<\/td>\n<td>12<\/td>\n<\/tr>\n<tr>\n<td>40-50<\/td>\n<td>2<\/td>\n<td>14<\/td>\n<\/tr>\n<tr>\n<td>50-60<\/td>\n<td>1<\/td>\n<td>15<\/td>\n<\/tr>\n<tr>\n<td>60-70<\/td>\n<td>0.5<\/td>\n<td>15.5<\/td>\n<\/tr>\n<tr>\n<td>70 and over<\/td>\n<td>0.1<\/td>\n<td>15.6<\/td>\n<\/tr>\n<tr>\n<td><\/td>\n<td>N= \u2211<em>f<\/em> =15.6<\/td>\n<td><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<p>&nbsp;<\/p>\n<p><span style=\"text-align: initial;font-size: 1em\">Now, m =<\/span><em style=\"text-align: initial;font-size: 1em\">N\/2=15.6\/2=7.8<\/em><\/p>\n<div><\/div>\n<div><span style=\"text-align: initial;font-size: 1em\">Cumulative frequency (c.<\/span><em style=\"text-align: initial;font-size: 1em\">f<\/em><span style=\"text-align: initial;font-size: 1em\">.) greater than 7.8 is 9. Therefore, the median class is 20-30.<\/span><\/div>\n<div><\/div>\n<div><span style=\"text-align: initial;font-size: 1em\">L1 = 20, L2 = 30, c = 5, f = 4 and L2 &#8211; L1 = 10 .<\/span><\/div>\n<div>\n<p>&nbsp;<\/p>\n<p>Now putting these values in the median formula we get<\/p>\n<p>Median = 20+104 (7.8-5) = 20+ 52 x 2.8<\/p>\n<p>=\u00a0\u00a0 20+5 x 1.4 = 27 Hence, median income is Rs 27,000.<\/p>\n<p>&nbsp;<\/p>\n<p><strong>Important mathematical property of median:<\/strong><\/p>\n<p>&nbsp;<\/p>\n<p>The sum of the deviations of the items from median, ignoring signs is the least.<\/p>\n<p>&nbsp;<\/p>\n<p><em>n<\/em><\/p>\n<p>i.e\u00a0\u00a0\u00a0 <em>\u00a0x<\/em><em>i<\/em><em>\u00a0\u00a0\u00a0\u00a0\u00a0 md <\/em>\u00a0is least.<\/p>\n<p><em>i<\/em>1<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p><strong>Merits of Median:<\/strong><\/p>\n<p>&nbsp;<\/p>\n<p>The median can be used in case of frequency distribution with open-end classes.<\/p>\n<p>&nbsp;<\/p>\n<p><span style=\"font-size: 1em;text-align: initial\">The median is not affected by extreme observations.<\/span><\/p>\n<p>&nbsp;<\/p>\n<p><span style=\"text-align: initial;font-size: 1em\">The value of median can be determined graphically where as the value of mean cannot be determined graphically.<\/span><\/p>\n<p>&nbsp;<\/p>\n<p><span style=\"text-align: initial;font-size: 1em\">It is easy to calculate and understand.<\/span><\/p>\n<\/div>\n<div>\n<p>&nbsp;<\/p>\n<p><strong>Demerits of Median:<\/strong><\/p>\n<p>&nbsp;<\/p>\n<p style=\"text-align: justify\">For calculating median it is necessary to arrange the data in some order, ascending or descending, where as other averages do not need arrangement.<\/p>\n<p>&nbsp;<\/p>\n<p>Since it is a positional average its value is not determined by all the observations in the series.<\/p>\n<p>&nbsp;<\/p>\n<p>Median is not capable for further algebraic calculations.<\/p>\n<p>&nbsp;<\/p>\n<p>The sampling stability of the median is less as compared to mean.<\/p>\n<p>&nbsp;<\/p>\n<p><strong>B.\u00a0\u00a0 <\/strong><strong>Quartiles:<\/strong><\/p>\n<p>&nbsp;<\/p>\n<p style=\"text-align: justify\">There are three quartiles, <em>i.e.<\/em> Q1, Q2 and Q3 which divide the total data into four equal parts when it has been orderly arranged. Q1, Q2 and Q3 are termed as first quartile, second quartile and third quartile or lower quartile, middle quartile and upper quartile, respectively.<\/p>\n<p>&nbsp;<\/p>\n<p style=\"text-align: justify\">The first quartile, Q1, separates the first one-fourth of the data from the upper three-fourths and is equal to the 25th percentile. The second quartile, Q2, divides the data into two equal parts (like median) and is equal to the 50th percentile. The third quartile, Q3, separates the first three-quarters of the data from the last quarter and is equal to 75th percentile.<\/p>\n<p>&nbsp;<\/p>\n<p><strong>Calculation of Quartiles:<\/strong><\/p>\n<p>&nbsp;<\/p>\n<p>The calculation of quartiles is done exactly in the same manner as it is in case of the\u00a0<span style=\"font-size: 1em;text-align: initial\">calculation of median.<\/span><\/p>\n<\/div>\n<div>\n<p>&nbsp;<\/p>\n<p>The different quartiles can be found using the formula given below:<\/p>\n<\/div>\n<div>\n<p>&nbsp;<\/p>\n<p>Where,<\/p>\n<\/div>\n<div>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-61\" src=\"http:\/\/mgmtp15.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/81\/2018\/10\/2-19.png\" alt=\"\" width=\"323\" height=\"75\" srcset=\"https:\/\/ebooks.inflibnet.ac.in\/mgmtp15\/wp-content\/uploads\/sites\/81\/2018\/10\/2-19.png 323w, https:\/\/ebooks.inflibnet.ac.in\/mgmtp15\/wp-content\/uploads\/sites\/81\/2018\/10\/2-19-300x70.png 300w, https:\/\/ebooks.inflibnet.ac.in\/mgmtp15\/wp-content\/uploads\/sites\/81\/2018\/10\/2-19-65x15.png 65w, https:\/\/ebooks.inflibnet.ac.in\/mgmtp15\/wp-content\/uploads\/sites\/81\/2018\/10\/2-19-225x52.png 225w\" sizes=\"auto, (max-width: 323px) 100vw, 323px\" \/><\/p>\n<p>l1=\u00a0 lower limit of ith quartile class<\/p>\n<p>&nbsp;<\/p>\n<p>l2=\u00a0\u00a0 upper limit of ith quartile class<\/p>\n<p>&nbsp;<\/p>\n<p><em style=\"text-align: initial;font-size: 1em\">c <\/em><span style=\"text-align: initial;font-size: 1em\">= cumulative frequency of the class preceding the ith quartile class<\/span><\/p>\n<p>&nbsp;<\/p>\n<p><em style=\"text-align: initial;font-size: 1em\">f <\/em><span style=\"text-align: initial;font-size: 1em\">= frequency of ith quartile class.<\/span><\/p>\n<\/div>\n<div>\n<p>&nbsp;<\/p>\n<p><strong>C.\u00a0 <\/strong><strong>Deciles<\/strong><\/p>\n<p>&nbsp;<\/p>\n<p>Deciles are the partition values which divide the arranged data into ten equal parts.<\/p>\n<p>&nbsp;<\/p>\n<p>There are nine deciles <em>i.e.<\/em> D1, D2, D3\u2026\u2026..\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 D9\u00a0 and 5th\u00a0 decile is same as median or<\/p>\n<p>&nbsp;<\/p>\n<p>Q2, because it divides the data in two equal parts.<\/p>\n<p>&nbsp;<\/p>\n<p><strong>Calculation of Deciles<\/strong>:<\/p>\n<p>&nbsp;<\/p>\n<p>The calculation of deciles is done exactly in the same manner as it is in case of calculation of median.<\/p>\n<p>&nbsp;<\/p>\n<p>The different deciles can be found using the formula given below:<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-62\" src=\"http:\/\/mgmtp15.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/81\/2018\/10\/2-20.png\" alt=\"\" width=\"388\" height=\"81\" srcset=\"https:\/\/ebooks.inflibnet.ac.in\/mgmtp15\/wp-content\/uploads\/sites\/81\/2018\/10\/2-20.png 388w, https:\/\/ebooks.inflibnet.ac.in\/mgmtp15\/wp-content\/uploads\/sites\/81\/2018\/10\/2-20-300x63.png 300w, https:\/\/ebooks.inflibnet.ac.in\/mgmtp15\/wp-content\/uploads\/sites\/81\/2018\/10\/2-20-65x14.png 65w, https:\/\/ebooks.inflibnet.ac.in\/mgmtp15\/wp-content\/uploads\/sites\/81\/2018\/10\/2-20-225x47.png 225w, https:\/\/ebooks.inflibnet.ac.in\/mgmtp15\/wp-content\/uploads\/sites\/81\/2018\/10\/2-20-350x73.png 350w\" sizes=\"auto, (max-width: 388px) 100vw, 388px\" \/><\/p>\n<p>&nbsp;<\/p>\n<p>Where,<\/p>\n<p>&nbsp;<\/p>\n<p><span style=\"font-size: 1em;text-align: initial\">l1=\u00a0 lower limit of ith decile class<\/span><\/p>\n<p><span style=\"text-align: initial;font-size: 1em\">l2=\u00a0 upper limit of ith decile class<\/span><\/p>\n<p><em style=\"text-align: initial;font-size: 1em\">c <\/em><span style=\"text-align: initial;font-size: 1em\">= cumulative frequency of the class preceding the ith decile class<\/span><\/p>\n<p><em style=\"text-align: initial;font-size: 1em\">f <\/em><span style=\"text-align: initial;font-size: 1em\">= frequency of ith decile class.<\/span><\/p>\n<\/div>\n<div>\n<p>&nbsp;<\/p>\n<p><strong>D. Percentiles<\/strong><\/p>\n<p>&nbsp;<\/p>\n<p style=\"text-align: justify\">Percentiles are the values which divide the arranged data into hundred equal parts. There are 99 percentiles <em>i.e.<\/em> P1, P2, P3, \u2026\u2026..,P99. The 50th percentile divides the series into two equal parts and P50 = D5 = Median.<\/p>\n<p>&nbsp;<\/p>\n<p>Similarly the value of Q1 = P25 and value of Q3 = P75<\/p>\n<p>&nbsp;<\/p>\n<p><strong>Calculation of Percentiles:<\/strong><\/p>\n<p>&nbsp;<\/p>\n<p>The different percentiles can be found using the formula given below:<\/p>\n<\/div>\n<div>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-63\" src=\"http:\/\/mgmtp15.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/81\/2018\/10\/2-21.png\" alt=\"\" width=\"419\" height=\"88\" srcset=\"https:\/\/ebooks.inflibnet.ac.in\/mgmtp15\/wp-content\/uploads\/sites\/81\/2018\/10\/2-21.png 419w, https:\/\/ebooks.inflibnet.ac.in\/mgmtp15\/wp-content\/uploads\/sites\/81\/2018\/10\/2-21-300x63.png 300w, https:\/\/ebooks.inflibnet.ac.in\/mgmtp15\/wp-content\/uploads\/sites\/81\/2018\/10\/2-21-65x14.png 65w, https:\/\/ebooks.inflibnet.ac.in\/mgmtp15\/wp-content\/uploads\/sites\/81\/2018\/10\/2-21-225x47.png 225w, https:\/\/ebooks.inflibnet.ac.in\/mgmtp15\/wp-content\/uploads\/sites\/81\/2018\/10\/2-21-350x74.png 350w\" sizes=\"auto, (max-width: 419px) 100vw, 419px\" \/><\/p>\n<p>Where,<\/p>\n<\/div>\n<div>\n<p>l1=\u00a0 lower limit of ith percentile class<\/p>\n<p>l2=\u00a0 upper limit of ith percentile class<\/p>\n<p><em style=\"text-align: initial;font-size: 1em\">c <\/em><span style=\"text-align: initial;font-size: 1em\">= cumulative frequency of the class preceding the ith percentile class<\/span><\/p>\n<p><em style=\"text-align: initial;font-size: 1em\">f <\/em><span style=\"text-align: initial;font-size: 1em\">= frequency of ith percentile class.<\/span><\/p>\n<\/div>\n<p><strong style=\"text-align: initial;font-size: 1em\">Merits of Quartiles, Deciles and Percentiles:<\/strong><\/p>\n<div>\n<p>&nbsp;<\/p>\n<p>These positional values can be directly determined in case of open end class intervals.<\/p>\n<p>&nbsp;<\/p>\n<p style=\"text-align: justify\">These positional values can be calculated easily in absence of some data. These are helpful in the calculation of measures of skewness.<\/p>\n<p>&nbsp;<\/p>\n<p>These are not affected very much by the extreme items. These can be located graphically.<\/p>\n<p>&nbsp;<\/p>\n<p><strong>Demerits of Quartiles, Deciles and Percentiles:<\/strong><\/p>\n<p>&nbsp;<\/p>\n<p>These values are not easily understood by a common man.<\/p>\n<p>&nbsp;<\/p>\n<p>These values are not based on all the observations of a series.<\/p>\n<p>&nbsp;<\/p>\n<p>These values cannot be computed if items are not given in ascending or descending order.<\/p>\n<p>&nbsp;<\/p>\n<p>These values have less sampling stability.<\/p>\n<p>&nbsp;<\/p>\n<p><strong>E. <\/strong><strong>Ogives<\/strong><\/p>\n<p>&nbsp;<\/p>\n<p>An Ogive is a way to graph information showing cumulative frequencies. It shows how many of values of the data are below certain boundary.<\/p>\n<p>&nbsp;<\/p>\n<p style=\"text-align: justify\"><strong>Construction of an Ogive: <\/strong>To make an ogive, first a cumulative-frequency table is constructed. Vertical scale (y-axis) on the graph represents cumulative frequencies and horizontal scale (x-axis) represents variable of interest.<\/p>\n<p>&nbsp;<\/p>\n<p style=\"text-align: justify\"><strong>Less than type Ogive curve: <\/strong>If we start from the upper limit of class intervals and then add class frequencies to get cumulative frequency. Then such a distribution is less than type cumulative frequency distribution and plotting it on graph gives a less than type ogive curve. The less than type ogive looks like an elongated &#8216;S&#8217;.<\/p>\n<p>&nbsp;<\/p>\n<p style=\"text-align: justify\"><strong style=\"text-align: initial;font-size: 1em\">More than type Ogive curve: <\/strong><span style=\"text-align: initial;font-size: 1em\">If we start from the lower limits of class intervals and then subtract class frequencies from the cumulative frequency. Then such a distribution is more than type cumulative frequency distribution and plotting it on graph gives a more than type ogive curve. More than type ogive looks like an elongated &#8216;S&#8217; turned upside down.<\/span><\/p>\n<\/div>\n<div>\n<p>&nbsp;<\/p>\n<p><strong>Determining the Median graphically<\/strong><\/p>\n<p>&nbsp;<\/p>\n<p>Median can also be determined graphically by using ogives through two methods given below.<\/p>\n<p>&nbsp;<\/p>\n<p><strong>Method-1:<\/strong><\/p>\n<p>&nbsp;<\/p>\n<p>Step-1: Draw two ogives- one by less than method and other by more than method.<\/p>\n<p>&nbsp;<\/p>\n<p>Step-2: From the point where both these curves intersect each other draw a perpendicular on the X-axis.<\/p>\n<p>&nbsp;<\/p>\n<p>Step -3: The point where this perpendicular touches the X-axis gives the value of median.<\/p>\n<p>&nbsp;<\/p>\n<p><strong>Method-2:<\/strong><\/p>\n<p>&nbsp;<\/p>\n<p>Step-1: Draw only one ogive by less than method or more than method by taking variable on the X-axis and cumulative frequency on the Y-axis.<\/p>\n<\/div>\n<div>\n<p>&nbsp;<\/p>\n<p>Step-2: Determine the value of N\/2.<\/p>\n<\/div>\n<div>\n<p>&nbsp;<\/p>\n<p>Step-3: Locate this value on the Y-axis and from it draw a line parallel to X-axis which meets the ogive<\/p>\n<\/div>\n<p>&nbsp;<\/p>\n<p><span style=\"text-align: initial;font-size: 1em\">Step -4: The point where this parallel line touches the ogive from it drop a perpendicular on X-axis. This point on X-axis gives the value of median.<\/span><\/p>\n<div>\n<p>&nbsp;<\/p>\n<p>Similarly, the other partition values like quartiles, deciles, etc can be also determined graphically.<\/p>\n<p>&nbsp;<\/p>\n<p><strong>F.\u00a0\u00a0 <\/strong><strong>Mode<\/strong><\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p style=\"text-align: justify\">The value of variable which occurs most frequently in data is called Mode. The concept of mode is often used in determining sizes. As an example, the most common shoe size is 6 or the most common shirt size is 42. It is a very appropriate measure of central tendency for nominal data.<\/p>\n<p>&nbsp;<\/p>\n<p><strong>Calculation of Mode &#8211; Ungrouped Data:<\/strong><\/p>\n<p>&nbsp;<\/p>\n<p>In this case mode is obtained by inspection.<\/p>\n<p>&nbsp;<\/p>\n<p><strong>Example 2:- <\/strong>The blood pressure of 9 patients is as follows:<\/p>\n<p>&nbsp;<\/p>\n<p>86, 87, 80, 86, 76, 86, 90, 88, 86.<\/p>\n<p>&nbsp;<\/p>\n<p>Calculate its mode.<\/p>\n<p>&nbsp;<\/p>\n<p><strong>Solution<\/strong><\/p>\n<p>&nbsp;<\/p>\n<p>The mode value is 86, as it occurs maximum times (i.e.4 times).<\/p>\n<p>&nbsp;<\/p>\n<p><strong>Note: <\/strong>In certain cases there may not be a mode or there may be more than one mode.<\/p>\n<\/div>\n<p>Example 3:<\/p>\n<p>&nbsp;<\/p>\n<div>a) 40, 44,57,78,84 (no mode)<br \/>\nb) 3, 4, 5, 5, 4, 2, 1 (modes 4 and 5)<br \/>\nc) 8, 8, 8, 8, 8 (no mode)<\/div>\n<p>&nbsp;<\/p>\n<p style=\"text-align: justify\"><span style=\"text-align: initial;font-size: 1em\">A series of data, having one mode is called \u2018unimodal\u2019 and a series of data having two modes is called \u2018bimodal\u2019. It may also have several modes and be called \u2018multimodal\u2019.<\/span><\/p>\n<div>\n<p>&nbsp;<\/p>\n<p><strong>Calculation of Mode \u2013 Grouped Data<\/strong>:<\/p>\n<p>&nbsp;<\/p>\n<p style=\"text-align: justify\">In case of grouped data, modal class is determined by inspection or by preparing grouping and analysis tables. Then we apply the following formula.<\/p>\n<p>&nbsp;<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-64\" src=\"http:\/\/mgmtp15.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/81\/2018\/10\/2-22.png\" alt=\"\" width=\"518\" height=\"81\" srcset=\"https:\/\/ebooks.inflibnet.ac.in\/mgmtp15\/wp-content\/uploads\/sites\/81\/2018\/10\/2-22.png 518w, https:\/\/ebooks.inflibnet.ac.in\/mgmtp15\/wp-content\/uploads\/sites\/81\/2018\/10\/2-22-300x47.png 300w, https:\/\/ebooks.inflibnet.ac.in\/mgmtp15\/wp-content\/uploads\/sites\/81\/2018\/10\/2-22-65x10.png 65w, https:\/\/ebooks.inflibnet.ac.in\/mgmtp15\/wp-content\/uploads\/sites\/81\/2018\/10\/2-22-225x35.png 225w, https:\/\/ebooks.inflibnet.ac.in\/mgmtp15\/wp-content\/uploads\/sites\/81\/2018\/10\/2-22-350x55.png 350w\" sizes=\"auto, (max-width: 518px) 100vw, 518px\" \/><\/p>\n<p><em>f <\/em>0 =frequency of the class preceding the modal class.<\/p>\n<p>&nbsp;<\/p>\n<p><em>f <\/em>2 = frequency of the class succeeding the modal class.<\/p>\n<p>&nbsp;<\/p>\n<p><em>i <\/em>= size of the class.<\/p>\n<p>&nbsp;<\/p>\n<p><em style=\"text-align: initial;font-size: 1em\">f<\/em><span style=\"text-align: initial;font-size: 1em\">1 =frequency of the modal class<\/span><\/p>\n<p>&nbsp;<\/p>\n<p><span style=\"font-size: 1em\">l1 = lower limit of the modal class.<\/span><\/p>\n<\/div>\n<div>\n<p>&nbsp;<\/p>\n<p><strong>Note:<\/strong><\/p>\n<p>&nbsp;<\/p>\n<p style=\"text-align: justify\">1)\u00a0\u00a0\u00a0 While applying the above formula for calculating mode, it is necessary to see that the class intervals are uniform throughout. If they are unequal they should first be made equal on the assumption that the frequencies are equally distributed throughout.<\/p>\n<p>&nbsp;<\/p>\n<p>2)\u00a0\u00a0\u00a0 In case of bimodal distribution the mode can\u2019t be found.<\/p>\n<p>&nbsp;<\/p>\n<p><strong style=\"text-align: justify;font-size: 1em\">Finding mode in case of bimodal distribution: <\/strong><span style=\"text-align: justify;font-size: 1em\">In a bimodal distribution the value of mode can not be determined by the help of the above formulae. In this case the mode can be determined by using the empirical relation given below.<\/span><\/p>\n<\/div>\n<div>\n<p>&nbsp;<\/p>\n<p><strong>Mode = 3Median &#8211; 2Mean<\/strong><\/p>\n<p>&nbsp;<\/p>\n<p>And the mode which is obtained by using the above relation is called <strong>\u2018Empirical<\/strong> <strong>mode\u2019<\/strong><\/p>\n<p>&nbsp;<\/p>\n<p><strong>Merits of Mode:<\/strong><\/p>\n<p>&nbsp;<\/p>\n<p>It is easy to calculate and simple to understand. It is not affected by the extreme values.<\/p>\n<p>&nbsp;<\/p>\n<p>The value of mode can be determined graphically.<\/p>\n<p>&nbsp;<\/p>\n<p>Its value can be determined in case of open-end class interval.<\/p>\n<p>&nbsp;<\/p>\n<p><strong>Demerits of Mode<\/strong>:<\/p>\n<p>&nbsp;<\/p>\n<p>It is not suitable for further mathematical treatments. The value of mode cannot always be determined.<\/p>\n<p>&nbsp;<\/p>\n<p>The value of mode is not based on each and every item of the series. The mode is not rigidly defined.<\/p>\n<p>&nbsp;<\/p>\n<p><strong>Summary<\/strong><\/p>\n<p>&nbsp;<\/p>\n<p style=\"text-align: justify\">Partition values divide the data, when arranged in either ascending order or descending order, into different number of equal parts. Median is the middle value in a set of arranged data. The place of the median in a series is such that an equal number of items lie on either side of it, i.e. it splits the\u00a0<span style=\"text-align: initial;font-size: 1em\">observations into two halves. We can also say that 50% of the observations lie above median value, while rest 50% of the observations lie below median value. Quartiles divide the total data into four equal parts when it has been orderly arranged. The first quartile, Q1, separates the first one-fourth of the data from the upper three-fourths and is equal to the 25th percentile. The second quartile, Q2, divides the data into two equal parts (like median) and is equal to the 50th percentile. The third quartile, Q3, separates the first three-quarters of the data from the last quarter and is equal to 75th percentile. Deciles are the partition values which divide the arranged data into ten equal parts whereas percentiles divide the data into hundred equal parts. Ogives are cumulative frequency graphs which help in finding different partition values graphically.<\/span><\/p>\n<\/div>\n<p>&nbsp;<\/p>\n<p style=\"text-align: justify\">Mode is the value of variable which occurs most frequently in data. The concept of mode is often used in determining sizes. It is a very appropriate measure of central tendency for nominal data.<\/p>\n<p>&nbsp;<\/p>\n<p style=\"text-align: center\"><strong>Learn More:<\/strong><\/p>\n<ol>\n<li><em>Business Research Methods\u2019 Authored by Naval Bajpai, Published by Pearson\u2019s India PHI<\/em><\/li>\n<li><em>Business Statistics Authored by Dr. K.L. Gupta, Published by Nirupam Publications.<\/em><\/li>\n<li><em>Business Statistics Authored by G.C. Beri, Published by TMH Publications.<\/em><\/li>\n<li><em style=\"text-align: initial;font-size: 1em\">Statistics For Managers using Microsoft Excel by David M. Levine David F. Stephan Timothy C. Krehbiel Mark L. Berenson, Published by PEARSON<\/em><\/li>\n<li><em style=\"text-align: initial;font-size: 1em\">Business Statistics by Ken Black, Published by John Wiley &amp; Sons, Inc<\/em><\/li>\n<\/ol>\n","protected":false},"author":3,"menu_order":7,"template":"","meta":{"_acf_changed":false,"pb_show_title":"on","pb_short_title":"","pb_subtitle":"","pb_authors":["sanjay-mishra"],"pb_section_license":""},"chapter-type":[],"contributor":[60],"license":[],"class_list":["post-57","chapter","type-chapter","status-publish","hentry","contributor-sanjay-mishra"],"part":3,"_links":{"self":[{"href":"https:\/\/ebooks.inflibnet.ac.in\/mgmtp15\/wp-json\/pressbooks\/v2\/chapters\/57","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/ebooks.inflibnet.ac.in\/mgmtp15\/wp-json\/pressbooks\/v2\/chapters"}],"about":[{"href":"https:\/\/ebooks.inflibnet.ac.in\/mgmtp15\/wp-json\/wp\/v2\/types\/chapter"}],"author":[{"embeddable":true,"href":"https:\/\/ebooks.inflibnet.ac.in\/mgmtp15\/wp-json\/wp\/v2\/users\/3"}],"version-history":[{"count":4,"href":"https:\/\/ebooks.inflibnet.ac.in\/mgmtp15\/wp-json\/pressbooks\/v2\/chapters\/57\/revisions"}],"predecessor-version":[{"id":66,"href":"https:\/\/ebooks.inflibnet.ac.in\/mgmtp15\/wp-json\/pressbooks\/v2\/chapters\/57\/revisions\/66"}],"part":[{"href":"https:\/\/ebooks.inflibnet.ac.in\/mgmtp15\/wp-json\/pressbooks\/v2\/parts\/3"}],"metadata":[{"href":"https:\/\/ebooks.inflibnet.ac.in\/mgmtp15\/wp-json\/pressbooks\/v2\/chapters\/57\/metadata\/"}],"wp:attachment":[{"href":"https:\/\/ebooks.inflibnet.ac.in\/mgmtp15\/wp-json\/wp\/v2\/media?parent=57"}],"wp:term":[{"taxonomy":"chapter-type","embeddable":true,"href":"https:\/\/ebooks.inflibnet.ac.in\/mgmtp15\/wp-json\/pressbooks\/v2\/chapter-type?post=57"},{"taxonomy":"contributor","embeddable":true,"href":"https:\/\/ebooks.inflibnet.ac.in\/mgmtp15\/wp-json\/wp\/v2\/contributor?post=57"},{"taxonomy":"license","embeddable":true,"href":"https:\/\/ebooks.inflibnet.ac.in\/mgmtp15\/wp-json\/wp\/v2\/license?post=57"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}