Case Title: A Construction Supply Firm’s ROP The manager of a construction supply found out from historical records that their reorder point revolves on two scenarios but not simultaneously: an ROP with variable lead time and an ROP with variable demand. In the case of variable lead time, he found out that the daily demand is constant for their cracked stones during lead time averages 13.3 cubic meters. In addition, he also found out that the demand during lead time is almost normally distributed with a mean of 33.25 cubic meters and a standard deviation of 6.65 cubic meters. In this scenario, he is willing to accept a stock out risk of not more than 3%. In the second scenario, the manager knew that the lead time for receiving new order for I-beam is 10 days. Demand for I-beam is variable during lead time could be described by a normal curve with a mean of 300 lengths and a standard deviation of 50 lengths. For I-beams, the manager is not willing to risk a stock out of more than 2%. In each scenario, 1. What is the appropriate z-value? 2. How much safety stock should be held? 3. What re-order point should be used?