Question

What is the variance of {9, -4, 7, 10, 3, -2}?

Answer 1

Variance is 28.472

Explanation:

Mean of `{9, -4, 7, 10, 3, -2}` is

`(9+(-4)+7+10+3+(-2))/6=23/6`

For Variance of a series `{x_1.x_2,...,x_6}`, whose mean is `barx`is given by

`(Sigma(x-barx)^2)/6` and hence it is

`1/6*{(23/6-9)^2+(23/6-(-4))^2+(23/6-7)^2+(23/6-10)^2+(23/6-3)^2+(23/6-(-2))^2}` or

`1/6*{(-31/6)^2+(47/6)^2+(-19/6)^2+(-37/6)^2+(5/6)^2+(35/6)^2}`

= `1/6*{961/36+2209/36+361/36+1369/36+25/36+1225/36}`

= `1/6*(6150/36)=28.472`