The purchasing agent has ascertained that the usage of floppy disks in the company is approximately normally distributed, with a mean of 30 per working day and a variance of 16. The company operates 240 days per year. Floppy disks are obtained from a supplier who is very reliable, when an order is placed (on day 0), it is always received on the fifth working day. The company cannot afford to run out of floppy disks, and the purchasing agent has established a 99.5 percent service level