2.2 Cars are shipped from three distribution centers to five dealers. The shipping cost is based on the mileage between the sources and the destinations, and is independent of whether the truck makes the trip with partial or full loads; enclosed table summarizes the mileage between the distribution centers and the dealers together with the monthly supply and demand figures given in number of cars. A full truck load includes 18 cars. The transportation cost per truck mile is $25. Dealer 2 3 4 5 Supply 100 150 200 140 35 400 2 50 70 60 65 80 200 3 40 90 100 150 130 150 Demand 100 200 150 160 140 Formulate the associated transportation model and determine the optimal shipping schedule.