Solve numerical problem 13.4 on Level production plan with sub-contracting. Data is given in 13.3. Note: Solve this problem in a tabular form. The columns are Period # (0, 1 to 8), Demand (Data in 13.3), Production (1,400 per month, Inventory of 200 on-hand beginning of Jan, Sub-Contract Quantity (whatever is short for the month), Extra Sub- Contract cost (based on $75 per unit). Compute the total sub-contracting cost Jan through August .. 13.4 Using the information in Problem 13.3, develop plan B. Produce at a constant rate of 1,400 units per month, which will meet minimum demands. Then use subcontracting, with addi- tional units at a premium price of $75 per unit. Evaluate this plan by computing the costs for January through August. Px ... 13.3 The president of Hill Enterprises, Terri Hill, projects the firm's aggregate demand requirements over the next 8 months as follows: Jan. Feb. Mar. Apr. 1,400 1,600 1,800 1,800 May June July Aug. 2,200 2,200 1,800 1,800