Economic Order Quantity points$)$:

A small metal framing shop uses welding rods at a uniform rate. The owner orders the rods from

a local supplier when the annual demand is about $1000$ pounds. To place an order, he has to

spend about $$3\mathrm{.}60$ for the phone call and other paper and manpower costs. The cost of a welding

rod is $$\frac{2}{?}$ pound and holding costs are assessed based on a $25\%$ annual rate.

$($a$)$ How much should the owner order each time to minimize his annual cost?