Problem #3 Disk Drives Limited (DDL) produces a line of internal Winchester disks for microcomputers. The drives use a 3.5-inch platter that DDL purchases from an outside supplier. Demand data and sales forecasts indicate that the demand for the platters seems to be closely approximated by a normal distribution with weekly mean 38 and weekly standard deviation 11.403. The platters require a three-week lead time for receipt. DDL has been using a 40 percent annual interest charge to compute holding costs. The platters cost $18.80 each, order cost is $75.00 per order, and the company is currently using a stock-out (shortage) cost of $400.00 per platter. Assume that one year consists of 52 weeks. Applying original (Q, R) system, the optimal Q and R are calculated as follows: (Q*, R*) = (203, 171) a. What is the optimal safety stock level? b. What is the proportion that there's stock-out during the lead time? c. What is the proportion of demands that are not met? Use the result of (b). Problem #3 Disk Drives Limited (DDL) produces a line of internal Winchester disks for microcomputers. The drives use a 3.5-inch platter that DDL purchases from an outside supplier. Demand data and sales forecasts indicate that the demand for the platters seems to be closely approximated by a normal distribution with weekly mean 38 and weekly standard deviation 11.403. The platters require a three-week lead time for receipt. DDL has been using a 40 percent annual interest charge to compute holding costs. The platters cost $18.80 each, order cost is $75.00 per order, and the company is currently using a stock-out (shortage) cost of $400.00 per platter. Assume that one year consists of 52 weeks. Applying original (Q, R) system, the optimal Q and R are calculated as follows: (Q*, R*) = (203, 171) a. What is the optimal safety stock level? b. What is the proportion that there's stock-out during the lead time? c. What is the proportion of demands that are not met? Use the result of (b)