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

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Answer 1 · 2016-03-27T11:10:10

Variance is 28.472

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

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

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

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