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 determined that average waiting times will be 7 minutes with one salesperson, 4 minutes with two salespeople, 3 minutes with three salespeople, 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?