Suppose that previously collected traffic data indicated tha

Suppose that previously collected traffic data indicated that, during the afternoon rush hour, an average of 4 cars arrive at a toll bridge each second. If it is assumed that the cars arrive randomly, and can thus be modeled with a Poisson distribution, what is the probability that in the next second, NO cars will arrive.

Solution

lambda = mean number of cars crossing bridge each second

= 4

probability that no cars arrive in next second

= P(X=0)

= 4^0/0! * e^-4

= 0.0183