Refer to Problem D.22. A new registration manager, Lisa Houts, is hired who initiates a program to entertain the people in line with a juggler whom she pays $15/hour. This reduces the waiting costs to $50 per hour.

a) What is the optimal number of servers?

b) What is the cost for the system, per hour, at the optimal service level? .D.24 The Chattanooga Furniture store gets an average of 50 customers per shift. Marilyn Helms, the manager, wants to calculate whether she should hire 1, 2, 3, or 4 salespeople. She has deter- mined that average waiting times will be 7 minutes with one sales-

person, 4 minutes with two salespeople, 3 minutes with three sales- people, and 2 minutes with four salespeople. She has estimated the cost per minute that customers wait at $1. The cost per salesperson per shift (including fringe benefits) is $70. How many salespeople should be hired?