The Canadian government has built a large grain-shipping port at Churchill, Manitoba, on the Hudson Bay. Grain grown in southern Manitoba is carried by rail to Churchill during the open-water shipping season. Unfortunately the port is open only 50 days per year during July and August. This leads to some critical crew staffing decisions by management. The port has the capacity to load up to 7 ships simultaneously, provided that each loading bay has an assigned crew. The remote location and short shipping season results in a very high labor cost for each crew assigned, and management would like to minimize the number of crews. Ships arrive in a random pattern that can be modeled using the Poisson probability model. If a ship arrives and all available loading bays are filled, the ship will be delayed, resulting in a large cost that must be paid to the owner of the ship. This penalty was negotiated to encourage ship owners to send their ships to Churchill. Results of an initial analysis indicate that each ship requires six hours for loading by a single crew. The port can remain open only 50 days per year, and 500 ships must be loaded during this time. Each additional crew costs $180,000, and each boat delay costs $10,000. How many crews should be scheduled?