Problem 2 (30%). 4 cargo ships will be used for shipping goods from one port to 4 other ports (labeled 1, 2, 3, 4). Any ship can be used for making any one of these 4 trips. However, because of differences in the ships and cargos, the total cost of loading, transporting, and unloading the goods for the different ship-port combination is shown in the following table: Ship 1 2 3 4 1 $500 600 700 500 Port 2 3 $400 $600 600 700 500 700 400 600 4 $700 500 600 600 Solve this assignment problem to obtain the optimal assignment with mimimum cost. (Note if you solve this problem using Excel Solver, please provide the Excel screen shot. If you solve it manually, please show your steps)