The probability model below describes the number of thunderstorms that a certain town may experience during the month of August. $$\begin{array} { l | l l l l }
\text { Number of storms } & 0 & 1 & 2 & 3 \
\hline \text { Probability } & 0.1 & 0.3 & 0.5 & 0.1
\end{array}$$ How many storms can the town expect each August?
A)1.5
B)1.9
C)2.0
D)1.7
E)1.6

Question

The probability model below describes the number of thunderstorms that a certain town may experience during the month of August. $$\begin{array} { l | l l l l } 
\text { Number of storms } & 0 & 1 & 2 & 3 \
\hline \text { Probability } & 0.1 & 0.3 & 0.5 & 0.1
\end{array}$$ How many storms can the town expect each August?
A)1.5
B)1.9
C)2.0
D)1.7
E)1.6

Quizplus · Accepted Answer

To find the expected number of storms, multiply each number of storms by its probability and sum these products: $E(X) = 0(0.1) + 1(0.3) + 2(0.5) + 3(0.1) = 0 + 0.3 + 1.0 + 0.3 = 1.6$.