During the next 8 months, Metropolis Power Company forecasts the demands shown in the table below (measured in thousands of kwh):

Power will be supplied from the four generating facilities, GF1- GF4. The facilities are each characterized by a generating capacity, a monthly operating cost, a startup cost, and a shutdown cost. These are each shown in thousands in the table below. When a generator is in operation, it provides service at its full capacity, even if that exceeds demand. No operating cost is saved by partial (rather than full) use of a generator's capacity. At the beginning of each month, it is possible to shut down any of the facilities that have been operating or to start up any of the facilities that have been idle.

At the start of month 1, facilities GF1 and GF2 are in operation. What is the minimum total cost of providing the power demanded?

1 2 4 Month Demand 3 154 96 77 148 119 92 126 84 2. Facility Startup Shutdown Capacity Cost 3 GF1 GF2 8. 70 3 60 50 GF3 GF4 6. 3 40 3