A bank offers your firm a revolving credit arrangement for up to $$70$ million at an interest rate of $2\mathrm{.}3$ percent per quarter. The bank also requires you to maintain a compensating balance of $4$ percent against the unused portion of the credit line, to be deposited in a non$-$interest$-$bearing account. Assume you have a short$-$term investment account at the bank that pays $1\mathrm{.}20$ percent per quarter, and assume that the bank uses compound interest on its revolving credit loans.