The Chattanooga Furniture store gets an average of 80 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 8 minutes with one? salesperson, 6 minutes with two? salespeople, 4 minutes with three? salespeople, and 2 minutes with four salespeople. She has estimated the cost per minute that customers wait at $2. The cost per salesperson per shift? (including fringe? benefits) is $60.

One? Server:

                                                                                              Total cost per shift? = _____dollars.

Two? Servers:

                                                                                              Total cost per shift? = _____ dollars.

Three? Servers:

                                                                                              Total cost per shift? = _____ dollars.

Four? Servers:

                                                                                              Total cost per shift? = _____ dollars.

Based on the given? information, Marilyn has minimum total cost per shift with ______ salespeople.