$\begin{array}{1 1}(A)\; 6.63 \\(B)\;16 \\(C)\;22 \\(D)\; 44 \end{array} $

- The formula to calculate variance is $\sigma^2= \large\frac{\sum x^2}{n} - \bigg( \large\frac{\sum x}{n}\bigg)^2$

Given $n=60$

$\sum x =960$

$ \sum x^2 =18000$

$\sigma^2= \large\frac{\sum x^2}{n} - \bigg( \large\frac{\sum x}{n}\bigg)^2$

$\qquad= \large\frac{18000}{60} - \bigg(\frac{ 960}{60}\bigg)^2$

$\qquad= 300- 16^2$

$\qquad= 300- 256$

$\qquad= 44$

Hence D is the correct answer.

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