The longer a loan schedule lasts, the more interest you will pay. For a $21,000-car-loan at 9% APR (compounded monthly) for three years (36 monthly payments), how much will it incur in total interest? For the same loan amount, how much will it incur in total interest if the loan rate is over six years (72 payments)? a. Find the difference in total interest. b. Why would you be willing to pay this extra interest? a. What is the total interest at 9% APR over three years? $(Round to the nearest dollar.)