• 1.Apub uses a periodic review system where it checks the liquor stock every tuesday and place an order which arrives on thursday. the pub has observed that demand for beer averages 7 units per day with a standard deviation of 2 units, In any given week,they want to be 90% sure that they wont run out of beer before the order arrives. On tuesday if they have 10 units of beer on hand, how many units should they order?