4. Arnoff Enterprises manufactures the central processing unit (CPU) for a line of personal computers. The CPUs are manufactured in Seattle, Columbus, and New York and shipped to warehouses in Pittsburgh, Mobile, Denver, Los Angeles, and Washington, D.C., for fur- ther distribution. The following table shows the number of CPUs available at each plant, the number of CPUs required by each warehouse, and the shipping costs (dollars per unit): Warehouse Los CPUs Plant Pittsburgh Mobile Denver Angeles Washington Available Seattle 10 20 9 10 9000 Columbus N 10 30 6 4000 New York 20 10 4 8000 CPUs Required 3000 5000 4000 6000 3000 21,000 2834800 2012/11/07 168.20.218.73 a. Develop a network representation of this problem. b. Determine the amount that should be shipped from each plant to each warehouse to minimize the total shipping cost. c. The Pittsburgh warehouse just increased its order by 1000 units, and Arnoff author rized the Columbus plant to increase its production by 1000 units. Will this production increase lead to an increase or decrease in total shipping costs? Solve for the new optimal solution