42. A company is using fixed-order quantity system of inventory management. For one of the items, the re-order quantity is 400 units and the re-order level is 350 units. The weekly demand of the product is known to be normally distributed with a mean of 100 units and a standard deviation equal to 40 units.

Given that the lead time is equal to 3 weeks, determine the service level offered. If a service level of 97. 7% is required, what re-order level be selected?