Your firm has a choice of three locations in which to operate a manufacturing facility. Four customers exist with a known demand for your product. Each potential plant location has an associated monthly operating cost and shipping routes to the demand cities have varying costs. In addition, each potential plant will have a shipping capacity which must not be exceeded. You need to determine which plant(s) to open and how much product to send from each open plant to each customer to minimize total shipping costs and fixed plant operating costs.