What is the standard deviation of {1, 2, 3, 4, 5}?

1 Answer
Nov 1, 2015

The answer is 66.

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)^21nni=1x2i(1nni=1xi)2

where nn is the total number of values in the given data set.
In your given data we have n = 5n=5 and the values of x_ixi's are {1,2,3,4,5}{1,2,3,4,5} .

So, your variance = 1/5 [ 1^2+2^2+ 3^2 +4^2+5^2] - (1/5 *[ 1+2+3+4+5])^2=15[12+22+32+42+52](15[1+2+3+4+5])2
= 11 -9=119
=6=6