Your manager has expressed worry about stocking out during order lead times. He has, up until now, just made sure to hold the average amount of inventory during lead time to cover expected demands. "I just can't figure it out," he says, "we're stocking out almost 50% of the time! That's crazy and our customers are unhappy. But I'm stocking the amount I expect to need, what's going wrong?" Calculate the additional amount of inventory that your manager needs to have at the beginning of lead time so that you only stock out 5% of the time. Data below: Demand is normally distributed, average of 500 units per day, standard deviation of 23 units per day. Lead time is 15 days Holding cost is 12% of cost of materials.