For this quesrion i got A,B,C correct. I only need assistance with D as it is not correct

After visiting several automobile dealerships, Richard selects the used car he wants. He likes its $13,900 price, but financing through the dealer is no bargain. He has $2,500 cash for a down payment so he needs an $11.400 loan. In shopping at several banks for an installment loan, he learns that interest on most automobile loans is quoted at add-on rates. That is, during the life of the loan, interest is paid on the full amount borrowed even though a portion of the principal has been paid back, Richard borrows 511,400 for a period of four years at an add-on interest rate of 10 percent (a) What is the total interest on Richard's loan? (Do not round intermediate calculations. Round your answer to the nearest whole number.) Totalterest 5 4,560 (b) What is the total cost of the car? (Do not round intermediate calculations. Round your answer to the nearest whole number.) Total cost 5 18.400 (c) What is the monthly payment? (Do not round Intermediate calculations. Round your answer to the nearest whole number.) Monthly payment 5 333 (d) What is the annual percentage rate (APR)? (Do not round intermediate calculations. Enter your answer as a percent rounded to 2 decimal places.) Amal percentage rate 10.59