Refer to the previous question. Suppose that Road Rambler’s phone system can only keep four calls on hold at any time, the average profit margin of each call is $55, and sales reps cost the company $12 per hour.

a. If callers who receive a busy signal take their business elsewhere, how much money is the company losing per hour (on average) if it employed a single sales rep?
b. What is the net effect on average hourly profits if the company employs two sales reps instead of one?
c. What is the net effect on average hourly profits if the company employs three sales reps instead of one?
d. How many sales reps should the company employ if it wants to maximize profit?

Data From Previous Question:

Road Rambler sells specialty running shoes and apparel through catalogs and the Web. Customers can phone in orders at any time day or night, 7 days a week. During the 4 a.m. to 8 a.m. shift, a single sales rep handles all calls. During this time, calls arrive at a rate of 14 per hour following a Poisson distribution. It takes the sales rep an average of four minutes to process each call. The variability in service times is approximately exponentially distributed. All calls received while the sales rep is busy are placed in a queue.