The Following Table Presents the Probability Distribution of the Number $\sigma$

Multiple Choice

The following table presents the probability distribution of the number of vacations taken last year for a randomly chosen family. Compute the standard deviation $\sigma$ .
$\begin{array}{c|ccccc}x & 0 & 1 & 2 & 3 & 4 \\\hline P(x) & 0.06 & 0.67 & 0.18 & 0.07 & 0.02\end{array}$

A) 1.38
B) 1.32
C) 0.77
D) 0.60