Assume that you are the director of the inventory management department using a periodic review system in a hotel. Every Monday, you review the inventory and identify the needs of replenishment orders. For 1 gallon milks, it is known that lead time is 3 weeks, the demand is normally distributed with a mean of 4100 units, and the standard deviation is 100 units per week. You also know that the desired cycle-service level is 90%. Calculate the safety stock and target inventory level for 1 gallon milks.