What Is the Expected Number of Phone Calls Per Hour

Essay

What is the expected number of phone calls per hour based on the following distribution on the number of phone calls per hour?
$\begin{array}{ccccc} & \mathrm{~A} & \mathrm{~B} & \mathrm{C} & \mathrm{D} \\1 & \text { \# of phone calls } & \mathrm{P}(\# \text { of phone calls) } & \text { \# of phone calls } & \mathrm{P}(\# \text { of phone calls) } \\2 & 1 & 0.10 & 1 & 0.10 \\2&2& 0.40 & 2 & 0.50 \\4 & 3 & 0.30 & 3 & 0.80 \\5 & 4 & 0.15 & 4 & 0.95 \\6&5 & 0.05 & 5 & 1.00\end{array}$