Weekly demand for DVD-Rs at a retaller is normally distributed with a mean of 1000 hoxes and a standard devlation of 150 Currently, the store places orders to the suppler, with a reorder point of 4,200 boxes The order quantity to the supplier is fixed at 5,000 boxes Replenishment lead time Is 4 weeks fixed order cost per order ls $100 each box costs the retailer $10, and the inventory holding cost Is 25% per year Glven the problem parameters, what is the optimal order quantity the retaller should order?