What is the variance of {15, 14, 13, 13, 12, 10, 7}?

1 Answer
Nov 1, 2015

Variance of the data set is 6.29.

Explanation:

Note that the formula of variance for calculation purpose is

1/n sum_(i=1) ^n x_i^2 - (1/n sum_(i=1)^n x_i)^2

where n is the total number of values in the given data set.
In your given data we have n = 7 and the values of x_i's are {15, 14, 13, 13, 12, 10, 7} .

So, your variance = 1/7 [ 15^2+14^2+ 13^2 +13^2+12^2+10^2+7^2 ] - (1/7 *[ 15+14+13+13+12 +10 +7])^2
= 150. 29 -144
=6.29