#of monthly payments annual percentage rate (apr) 10% 11% 12% 13% 14% 15% 16% 17% 18% 17 7.67 8.45 9.24 10.03 10.82 11.62 12.42 13.23 14.04 18 8.10 8.93 9.77 10.61 11.45 12.29 13.14 13.99 14.85 your friend just purchased a new sports car for $32,000. he received $6,000 for his trade in and used that money as a down payment for the new sports car. he financed the vehicle at 10% apr over 48 months. he received a bonus check at work and paid off the loan after making 30 payments. use the actuarial method formula and the table above to determine the amount of unearned interest given that your monthly payment is $659.43.