Willow Brook National Bank operates a drive-up teller window that allows customers tocomplete bank transactions without getting out of their cars. On weekday mornings,arrivals to the drive-up teller window occur at random, with an arrival rate of 24 customersper hour or 0.4 customer per minute.a. What is the mean or expected number of customers that will arrive in a ?ve-minuteperiod?b. Assume that the Poisson probability distribution can be used to describe the arrivalprocess. Use the arrival rate in part (a) and compute the probabilities that exactly 0, 1,2, and 3 customers will arrive during a ?ve-minute period.c. Delays are expected if more than three customers arrive during any ?ve-minuteperiod. What is the probability that delays will occur?
