$10\mathrm{.}16.$ An item has a weekly demand of $240$ units throughout the year. The item has a unit value of $$42$ and the company uses $20\%$ of the item value for the annual inventory cost. When ordered, the setup cost to produce an order is $$600,$ and the production process is able to produce $500$ per week and deliver them weekly as produced. What is the economic order quantity?