Please help, don't know where to start Jordan's Restaurant orders lettuce once a week,on Wednesday,with delivery 2 days later,on Friday. Lettuce is

Please help, don't know where to start

Jordan's Restaurant orders lettuce once a week,on Wednesday,with delivery 2 days later,on Friday. Lettuce is used seven days a week, with an average daily use of 25 heads and a standard deviation of 3 heads. Determine what the stocking level and safety stock should be if the cafeteria manager wishes to have no more than a one percent chance of a stock-out during each review period.Assume that the demand during the lead time and review period is normally distributed