A health food store places an order every ten days for many of the bottles of vitamins it stocks. The manager of the drugstore wants a service level of 90%. The replenishment lead-time is 6 days. Average demand for their best- selling item is normally distributed with a mean of 20 bottles per day, and the standard deviation of demand is 10 bottles per day. Given that they have 128 in stock, at the time they have to place the next order, how much should be ordered? (orders are in whole bottles only)