an appliance store sells microwaves at a steady rate throughout the year. each microwave costs the store $65 per unit, with an annual holding cost of 20%. every time the store places an order for microwaves, they incur a $200 fixed cost for administrative and shipping costs (independent of the number of units ordered). each microwave sits in the store's inventory for an average of four weeks (assuming 52 weeks in a year). if the store uses an optimal order quantity, what is the store's yearly demand for microwaves?