Question

What is the variance of {7, 3, -1, 1, -3, 4, -2}?

Answer 1

Variance `sigma^2=542/49=11.0612`

Explanation:

Solve the mean `barx` first

`barx=(7+3+(-1)+1+(-3)+4+(-2))/7=9/7`

Solve Variance `sigma^2`

`sigma^2=((7-9/7)^2+(3-9/7)^2+(-1-9/7)^2+(1-9/7)^2+(-3-9/7)^2+(4-9/7)^2+(-2-9/7)^2)/7`

`sigma^2=542/49=11.0612`

God bless....I hope the explanation is useful.