Vision Company sells optical equipment. Blitz Company manufactures special glass lenses. Vision orders 11,400 lenses per year, 200 per week, at $35 per lens. Blitz covers all shipping costs. Vision earns 25% on its cash investments. The purchase-order lead time is 2.5 weeks. Vision sells 225 lenses per week. The following data are available:

Relevant ordering costs per purchase order $41.25

Relevant insurance, materials handling, breakage,

and so on, per year $ 4.50

What is the economic order quantity for Vision?