Question: Thomas Toys Ltd. uses a periodic review inventory management system. One important item for the company is building blocks, which sell, on average, five sets per day. However, the standard deviation of demand is two sets per day. The company checks the status of inventory for building blocks every 21 days. When blocks are reordered from the supplier, it takes 14 days to be replenished. Thomas has just checked its inventory and found that it currently has 160 sets in stock. The company desires to maintain a 97.5 percent service level. How many sets of building blocks should Thomas Toys order?