What Is the Probability That 3 or More Phone Calls

Essay

What is the probability that 3 or more phone calls are received in any hour of operation?
$\begin{array}{ccccc} & \mathrm{~A} & \mathrm{~B} & \mathrm{C} & \mathrm{D} \\1 & \text { \# of phone calls } & \mathrm{P}(\# \text { of phone calls) } & \text { \# of phone calls } & \mathrm{P}(\# \text { of phone calls) } \\2 & 1 & 0.10 & 1 & 0.10 \\2&2& 0.40 & 2 & 0.50 \\4 & 3 & 0.30 & 3 & 0.80 \\5 & 4 & 0.15 & 4 & 0.95 \\6&5 & 0.05 & 5 & 1.00\end{array}$