A recent college graduate buys a new car by borrowing $20,000 at 8.4%, compounded monthly, for 4 years. She decides to pay $513 instead of the monthly payment required by the loan. (a) What is the monthly payment required by the loan? (Round your answer to the nearest cent.) $ How much extra did she pay per month? (Round your answer to the nearest cent.) $ (b) How many $513 payments will she make to pay off the loan? (Round your answer up to the next whole number.) payments (c) How much will she save by paying $513 per month rather than the required payment? (Round your answer to the nearest cent.)