I know that for a you multiply 9x sq of 4 + 1 (lead time) but i get a wrong answer
Statewide Auto Parts uses a four-week periodic review system to reorder parts for its inventory stock. A one-week lead time is required to ﬁll the order. Demand for oneparticular part during the ﬁve-week replenishment period is normally distributed with a mean of 22 units and a standard deviation of 8 units. a. At a particular periodic review, 9 units are in inventory. The parts manager places an order for 17 units. What is the probability that this part will have a stock-out before anorder that is placed at the next four-week review period arrives? If required, round your answer to four decimal places. :l b. Assume that the company is willing to tolerate a 2.8% chance of a stock-out associated with a replenishment decision. How many parts should the manager have ordered inpart (a)? If required, round your answer to the nearest whole number. The manager should have ordered C] units. What is the replenishment level for the four-week periodic review system? What is the replenishment level for the four-week periodic review system? The replenishment level for the four-week periodic review system is C] .