Suppose the Number of Cars Passing Through a Toll Booth $p _ { n } = \frac { ( 23 ) ^ { n } } { n ! } e ^ { - 23 }$

True/False

Suppose the number of cars passing through a toll booth in a 10 minute interval is a Poisson random variable. If the average number of cars is 23, give an expression for the probability that n cars pass through the booth. Is $p _ { n } = \frac { ( 23 ) ^ { n } } { n ! } e ^ { - 23 }$ correct?