The owner of Go-Ride, Tom Rider, projects that within three years, demand for riding mowers will exceed supply by approximately 550 units a month. Projected demand and current capacities and unit costs are: ** WH = Warehouse ** Supply & Demand = mowers per month To / From WH1 WH2 WH3 WH4 Supply Plant A 10 27 7 14 250 Plant B 12 20 8 450 270 Demand 340 140 140 a. Formulate it as a linear programming problem. b. Use Excel and solve this problem to obtain the lowest-cost shipping schedule. What is the minimum shipping cost?