Ray took out a 60 month fixed installment loan $12,000 to open a new pet store. he paid no money down and began making monthly payments of $232. gray's business does better than expected and instead of making his 24th payment, ray wishes to repay his loan in full. a) determine the apr of the installment loan. b) how much interest will ray save by paying off his loan early? c) what is the total amount due to pay off the loan?