Question: Ashley's Department Store in Kansas City maintains a successful catalog sales department in which a clerk takes orders by telephone. If the clerk is occupied on one line, incoming phone calls to the catalog department are answered automatically be a recording machine and asked to wait. As soon as the clerk is free, the party that has waited the longest is transferred and answered first. Calls come in at a rate of 12 per hour. The clerk is capable of taking an order in an average of 4 minutes. Calls tend to follow a Poisson distribution, and service times tend to be exponential. The clerk is paid $10 an hour, but because of lost goodwill and sales, Ashley's loses about $50 per hour in customer time spent waiting for the clerk to take the order.

(a) What is the average time that the catalog customers must wait before their calls are transferred to the order clerk?
(B) What is the average number of callers waiting to place an order?
(C) Ashley's is considering adding a second clerk to take calls. The store would pay that person the same $10 per hour. Should it hire another clerk? Explain