Petromax Enterprises uses a continuous review inventory control system for one of its SKUs. The following information is available on the item. The firm operates 52 weeks in a year. Refer to the standard normal table for z-values. Demand =91,000 units/year Ordering cost =$38.00 /order Holding cost =$4.50/ unit/year Average lead time =4 weeks Standard deviation of weekly demand =225 units a. The economic order quantity for this item is units. (Enter your response rounded to the nearest whole number.) b. If Petromax wants to provide a 92% service level, the safety stock is units (enter your response rounded to the nearest whole number)