Exercise 3: (30 points) Weiss's paint store uses a (Q.B) inventory system to control its stock levels. For a particularly popular white latex paint, historical data show that the distribution of demand during lead time is approximately normal, with mean 40 and standard deviation 8. Replenishment lead time is about 3 weeks. The desired stock out risk is 2%. a. Find safety stock that is needed. (15 Points) b. Find the reorder point. (15 Points)