03Variance and Standard Deviation

03Variance and Standard Deviation - VARIANCE AND STANDARD...

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V ARIANCE AND S TANDARD D EVIATION There are other ways of measuring data other than measures of central tendency. One other ways is to use measures of dispersion, that is, a measure of the variability that exists in a data set. One reason to measure dispersion is to judge how well the average value depicts the data. Two sets of data can have the same mean, but be very different. For example look at these two sets of class test scores: Set 1: 23 45 67 75 84 96 Set 2: 53 59 67 68 69 74 The mean of both sets is 65, but it is easy to see that the scores in Set 1 are much more spread out. One measure of dispersion is the range of the data set, but this does not necessarily give us enough information about the data set because it only uses the minimum and maximum values in its calculation. Another measure of dispersion that is used is the variance . The calculation for variance involves using all the values in the data set. Population variance
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03Variance and Standard Deviation - VARIANCE AND STANDARD...

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