The Probability Model Below Describes the Number of Thunderstorms That $$\begin{array} { l | c c c c } \text { Number of storms } & 0 & 1 & 2 & 3 \\\hline \text { Probability } & 0.1 & 0.2 & 0.4 & 0.3\end{array}$$

Multiple Choice

The probability model below describes the number of thunderstorms that a certain town may experience during the month of August. $$\begin{array} { l | c c c c } \text { Number of storms } & 0 & 1 & 2 & 3 \\\hline \text { Probability } & 0.1 & 0.2 & 0.4 & 0.3\end{array}$$ What is the standard deviation of the number of storms in August?

A) 0.88
B) 0.94
C) 0.66
D) 0.75
E) 0.77