The demand for laptop computers at points of sale -open every day- is normal with a mean of 3 units per day and a standard deviation of 1.57 laptops per day. You are the new Operations Manager and you set a service level of 0.9 (use the closest z values in the normal table, or calculate it with Excel). Lead time is 2 days. a. Using a ROP model, what is the ROP that corresponds with the desired service level? b. When the inventory on hand is exactly the ROP, how many days of supply are on hand, assuming average demand? c. If a fixed-interval model is used instead of an ROP model, what order size would be needed, with an order interval of 10 days and 8 laptops on hand at the order time