Question

What is the variance of the following set of numbers?: {12, 19,19, 19, 20, 20, 21, 21, 21, 22, 22, 22, 22, 22, 22,23, 23, 23, 24, 25, 26, 26, 27, 27, 28, 32}

Answer 1

Variance (Population): `sigma^2 ~~ 20.9`

Explanation:

Population Variance (`color(black)(sigma^2`) is the average of the the squares of the differences between each population data item and the population mean.

For a population `{d_1, d_2, d_3, ...}` of size `n`
with a mean value of `mu`

`sigma^2 = (sum (d_i - mu)^2)/n`