Suppose That During a Certain Part of the Day, the Number

Short Answer

Suppose that during a certain part of the day, the number X of automobiles that arrive within any one minute at a tollgate is Poisson distributed, and $\operatorname { Pr } ( X = \mathrm { k } ) = \frac { 4 ^ { \mathrm { k } } \mathrm { e } ^ { - 4 } } { 1 \cdot 2 \cdot \ldots \cdot \mathrm { k } }$ . What is the average number of automobiles that arrive per minute?
Enter just an integer.