10 points) Lake Superior Mechanical Ltd. makes three similar products that all follow the same three-step manufacturing process of milling, inspection and drilling. Product Michigan requires 12 minutes of milling, 5 minutes of inspection and 10 minutes of drilling per unit. Product Ontario requires 10 minutes of milling, 4 minutes of inspection and 8 minutes of drilling per unit. Product Huron requires 8 minutes of milling, 4 minutes of inspection and 16 minutes of drilling. Lake Superior Mechanical has 20 hours available during the next period for milling, 15 hours for inspection and 24 hours for drilling. Product Michigan contributes $2.40 per unit to profit, Product Ontario contributes $2.50 per unit to profit and Product Huron contributes $3.00 per unit to profit. Required: a) Create an LP in Excel to determine the production mix of products in order to maximize total contribution to profits for the period. b) Solve the LP model using Solver. c) Find the range of optimality for the profit coefficient for each variable.