Question 7 (3 points) Saved In ABC store, the weekly demand for item X is random while the yearly demand is stable. The weekly demand for item X is normally distributed with a mean demand of 250 per week and a standard deviation of 40 per week. The store is open 50 weeks a year. The store pays the supplier $40 per unit. It costs the store $60 every time they place an order. Also, the cost of holding an item in inventory for one year has been estimated as 4% of the unit cost of the item. The lead time is 4 weeks. What level of safety stock (round to the nearest integer) should be held to maintain an annual service level of 99%? 138 79 64 83 None of these answer choices