5.11 Ellsworth Enterprises signed a contract to purchase 1500 sheets of steel from a local manufacturer every week. Ellsworth incurs an order cost of $40 each time it places an order with the manufacturer. The manufacturer sells the steel to Ellsworth for $100 per sheet. Ellworth's annual holding cost of inventory is $1.50 per sheet per year. What quantity should Ellworth order to minimize its ordering and holding costs