Dells call center is developing a staffing plan. The table below lists the minimum number of representatives required during each of the six four-hour periods in a day. Representatives work 8-hour shifts, which can start every 4 hours throughout the day.

TIME PERIOD NR. OF REPRESENTATIVES REQUIRED 12 A.M.4 A.M. 90 4 A.M.8 A.M. 215 8 A.M. 12 P.M. 250 12 P.M.4 P.M. 165 4 P.M.8 P.M. 300 8 P.M.12 A.M 125

a) Formulate a Linear Program that can be used to develop a staffing plan that minimizes the number of employees while meeting requirements. Clearly specify the decision variables, objective function, and constraints.

b) Create a spreadsheet model for this problem and solve it using Solver. What is an optimal solution?