3. Demand for an item is Normally distributed with a mean of 400 units per week and a standard deviation of 60 units. Order cost is $300, holding cost is $12 a unit per year, and lead-time is 2 weeks and constant. (Round Q and Safety Stock up to the nearest whole number) a. Describe a (Q, R) Policy that gives a 96% service level and indicate the cost of holding safety stock for this policy. b. How much would costs increase if the service level were 98%? c. Suppose that we plan to review the inventory every T weeks, where T is calculated based on the order quantity in a. (hint: cycle length (T) based on a fixed order quantity Q). Now, describe a (S, T) Policy that gives a 96% service level and indicate the cost of holding safety stock for this policy