Part A is correct just need help on the rest

Problem 14-7 (LO 14-5, 14-7) The Harvard Co-op orders sweatshirts... The Harvard Co-op orders sweatshirts with the Harvard University emblem on them which costs them $50 each. During a typical month, 900 sweatshirts are sold (this includes all styles and sizes ordered from a particular supplier). It costs $25 to place an order (for multiple sizes and styles) and 25 percent to carry sweatshirts in inventory for a year. The Co-op has discovered that it should establish a safety stock for its sweatshirts. It wants to use a reorder point system with a two-week lead time. The demand over a two-week interval has an average of 450 units. The standard deviation for a two week period is 250 units. a. What reorder point should the Co-op establish to ensure a 95 percent service level? (Round answer up to the nearest integer.) 863 units b. What reorder point should be established to ensure that no more than one stockout occurs in the course of a year? (Round answer up to the nearest integer.) units c. How much average inventory will the Co-op carry for part b? Include both cycle inventory and safety stock in your answer. (Round answer up to the nearest integer.) 5 units Cycle Inventory Safety Stock Average Inventory units units d. How often will the Co-op turn over its inventory, using the results from part c? (Round answer to 2 decimal places.) times per year