You’ve recently finished your MBA at the Darnit School. Naturally, you must purchase a new BMW immediately. The car costs about \($21,000.\) The bank quotes an interest rate of 15 percent APR for a 72-month loan with a 10 percent down payment. You plan on trading the car in for a new one in two years. What will your monthly payment be? What is the effective interest rate on the loan? What will the loan balance be when you trade the car in?