Nationwide Auto Parts uses a periodic review inventory control system for one of its stock items. The review interval is 6 weeks, and the lead time for receiving the materials ordered from its wholesaler is 3 weeks. Weekly demand is normally distributed, with a mean of 100 units and a standard deviation of 20 units. 1. What are the average and the standard deviation of demand during the protection interval? Average: (Rounded) 900 Standard deviation: (Rounded) 180 2. What should be the target inventory level if the firm desires 97.5 percent stockout protection? (Rounded Up) 1253 3. If 350 units were in stock at the time of a periodic review, how many units should be ordered? 903 Sam's Cat Hotel operates 52 weeks per year, 6 days per week, and uses a continuous review inventory system. It purchases kitty litter for $11.70 per bag. The following information is available about these bags. Demand = 90 bags/week Order cost = $54/order Annual holding cost =27 percent of cost Desired cycle-service level = 80 percent Lead time = 3 weeks (18 working days) Standard deviation of weekly demand = 15 bags Current on-hand inventory is 320 bags, with no open orders or backorders. 1. What is the EOQ? (Rounded) 55 2. What would be the average time between orders (in weeks)? (Rounded to 2 decimals) 0.61 3. What should R be? (Rounded Up) 292 4. An inventory withdrawal of 10 bags was just made. Is it time to reorder? No 5. The store currently uses a lot size of 500 bags (i.e.,Q=500). What is the annual holding cost of this policy? (Rounded to 2 decimals) 789.75 What is the annual ordering cost? (Rounded to 2 decimals) 505.44 6. What would be the annual cost saved by shifting from the 500-bag lot size to the EOQ? (Rounded to 2 decimals) 702.88