Ans: B
Note that adding a constant to all the data of a distribution would not affect the value of the variance. Note also that if we multiplying a constant to all the data of a distribution, the variance would be multiplied by the square of the constant. Hence, the new variance
Note that adding a constant to all the data of a distribution would not affect the value of the variance. Note also that if we multiplying a constant to all the data of a distribution, the variance would be multiplied by the square of the constant. Hence, the new variance
$\begin{array}{cl}
= & (-1)^2 \times 9 \\
= & 9
\end{array}$
