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, Lose Angeles, and Washington, D.C., for further 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 Plant Pitssburgh Mobile Denver Los Washington CPUs Angeles Available Seattle 10 20 9 10 9000 Columbus 2 10 8 30 6 4000 New 20 10 4 8000 York CPUs 3000 5000 4000 6000 3000 21.000 Required