16 A chemical manufacturer is developing three fertilizer compounds for the agricultural industry. The product codes for these three products are X1, X2 and X3 and the relevant information is summarized below: Chemical constituents: percentage make-up per ton Selling price per ton Nitrate Phosphate Potash Filler For three products X1 10 10 20 60 83 X2 10 20 10 60 81 X3 20 10 10 60 81 Input prices per ton Maximum available inputs in tons per month: Nitrate 150 Nitrate 1 200 Phosphate 60 Phosphate 2 000 Potash 120 Potash 2 200 Filler 10 Filler No limit The manufacturing costs for each type of fertilizer, excluding materials are N$11 per ton REQUIRED: Marks 16.1. Formulate and solve a linear programming model so that company may maximize contribution, indicate how many units of each product will be produced and what the contribution will be. 16.2. Calculate shadow prices for the constraints in your solution.