this is supply chain need it as sson as possible

Table of Z-values for normal distribution: Service level 90% 91% 92% 93% 94% 95% 96% 97% 98% 99% 99.99% z-value 1.29 1.34 1.41 1.48 1.56 1.65 1.75 1.88 2.00 2.33 3.00 Problem 3 (28 Points): Cassorla's Clothes sells a large number of white dress shirts. The shirts, which bear the store label, are shipped from a manufacturer in Los Angeles. The shirts cost $20 each and sell for $30 each. The cost of processing an order and receiving new goods amounts to $100, and it takes 4 weeks to receive a shipment. Monthly demand is approximately normally distributed with mean 200 and standard deviation 100. Assume a 20 percent annual interest rate for computing the holding cost. Assume four weeks in a month for your calculations. Hy Cassorla, the proprietor, says, I want to be sure that I never run out of dress shirts. I always try to keep at least two months' supply (400 units) in stock. That is, when my inventory drops below that level, I order another two months' supply. I've been using that method for 15 years, and it works." (a) What values of order quantity and reorder point is Hy Cassorla using currently to control the inventory of white dress shirts? What is the expected service level associated with this policy? (b) What is the expected total cost (fixed cost plus holding cost) per year with this policy? (c) Based on a 95 percent service level criterion, determine the optimal values of order quantity and reorder point. How much is the saving in the annual total cost of the optimal policy compared with the current policy. (d) Now suppose the company makes replenishment orders only at the beginning of every EVEN month. The replenishment lead time is still 4 weeks. Assume a 95 percent service level. Please find out the detailed optimal inventory control policy. Table of Z-values for normal distribution: Service level 90% 91% 92% 93% 94% 95% 96% 97% 98% 99% 99.99% z-value 1.29 1.34 1.41 1.48 1.56 1.65 1.75 1.88 2.00 2.33 3.00 Problem 3 (28 Points): Cassorla's Clothes sells a large number of white dress shirts. The shirts, which bear the store label, are shipped from a manufacturer in Los Angeles. The shirts cost $20 each and sell for $30 each. The cost of processing an order and receiving new goods amounts to $100, and it takes 4 weeks to receive a shipment. Monthly demand is approximately normally distributed with mean 200 and standard deviation 100. Assume a 20 percent annual interest rate for computing the holding cost. Assume four weeks in a month for your calculations. Hy Cassorla, the proprietor, says, I want to be sure that I never run out of dress shirts. I always try to keep at least two months' supply (400 units) in stock. That is, when my inventory drops below that level, I order another two months' supply. I've been using that method for 15 years, and it works." (a) What values of order quantity and reorder point is Hy Cassorla using currently to control the inventory of white dress shirts? What is the expected service level associated with this policy? (b) What is the expected total cost (fixed cost plus holding cost) per year with this policy? (c) Based on a 95 percent service level criterion, determine the optimal values of order quantity and reorder point. How much is the saving in the annual total cost of the optimal policy compared with the current policy. (d) Now suppose the company makes replenishment orders only at the beginning of every EVEN month. The replenishment lead time is still 4 weeks. Assume a 95 percent service level. Please find out the detailed optimal inventory control policy