Arnoff Enterprises manufactures the central processing unit (CPU) for a line of tablet computers. The CPUs are manufactured at three sites in China: Shanghai, Changchun and Nanchang and then shipped to warehouses in Singapore, Seattle, Lisbon, Sao Paulo and Dubai for further distribution. The following transportation tableau shows the number of CPUs available at each plant and the number of CPUs required by each warehouse. The shipping costs (dollars per unit) are also shown in each cell.

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 Singapore warehouse has just increased its order by 1000 units, and Arnoff has authorized the Changchun plant to increase its production by 1000 units. Will this change lead to an increase or decrease in total shipping costs? Solve for the new optimal solution.