a local supermarket sells a popular brand of shampoo at a fairly steady rate of 380 bottles per month. the cost of each bottle to the supermarket is 45 cents, and the cost of placing an order has been estimated at $8.50. assume that holding costs are based on a 25 percent annual interest rate. stock-outs of the shampoo are not allowed. Determine the optimal lot size the supermarket should order and total inventory cost. (15 ponts)