4. Consider the following transportation problem:
5. Steel mills in three cities produce the following amounts of steel:LocationWeekly Production (tons)
These mills supply steel to four cities, where manufacturing plants have the following demand:LocationWeekly Demand (tons)1. Detroit1302. St. Louis703. Chicago1804. Norfolk240620Shipping costs per ton of steel are as follows:To (cost)From1234A$14$ 9$16$18B118716C16121022Because of a truckers’ strike, shipments are prohibited from Birmingham to Chicago. Formulate this problem as a linear programming model and solve it by using the computer.
6. In Problem 5, what would be the effect on the optimal solution of a reduction in production capacity at the Gary mill from 320 tons to 290 tons per week?7. Coal is mined and processed at the following four mines in Kentucky, West Virginia, and Virginia:LocationCapacity (tons)