You are in charge of inventory control of a highly successful product retailed by your firm. Weekly demand for this item​ varies, with an average of units and a standard deviation of units. It is purchased from a wholesaler at a cost of ​$ per unit. The supply lead time is weeks. Placing an order costs ​$​, and the inventory carrying rate per year is percent of the​ item's cost. Your firm operates days per​ week, weeks per year. Refer to the standard normal tableLOADING... for​ z-values. a. What is the optimal ordering quantity for this​ item? nothing units. ​(Enter your response rounded to the nearest whole​ number.)