a$.$ Fiona Enterprises uses $9,700$ machine parts per month and then reorders another $9,700.$ The relevant carrying cost per machine part is $$12\mathrm{.}75,$ and the fixed order cost per order is $$2,240.$ What is the EOQ for Fiona Enterprises? $(3$ points$)$

b$.$ What is the implied interest rate when a customer has to pay $$25,000$ for a term of sale of $1/15$ net $30?$