Question

How to get the percent of scores in one and two standard deviations of the mean

Answer 1

For finding the percent of scores in one and two standard deviations of the mean, follow the following procedure:

(a) For finding the percent of scores in one standard deviation of the mean, first of all find the two values such as (Mean – 1*SD) and (Mean + 1*SD). Then count all numbers lies within these two values. Then simply find out the percent of required scores in one standard deviation of the mean as below:

Required percentage = [Number lies within two values / Total number of scores ] * 100

You will get required percentage.

Suppose, you find 15 scores lies within (Mean – 1*SD) and (Mean + 1*SD) and total scores are 25.

Then required percentage = (15/25)*100 = 60%

(b) For finding the percent of scores in two standard deviations of the mean, first of all find the two values such as (Mean – 2*SD) and (Mean + 2*SD). Then count all numbers lies within these two values. Then simply find out the percent of required scores in two standard deviations of the mean as below:

Required percentage = [Number lies within two values / Total number of scores ] * 100

You will get required percentage.

Suppose, you find 20 scores lies within (Mean – 2*SD) and (Mean + 2*SD) and total scores are 25.

Then required percentage = (20/25)*100 = 80%