John Brooks a recent ME graduate from Central Michigan, bought an SUV for $30,000 with a down payment of $10,000. John had a little business on the side and did not have a girlfriend when he was at school and ehnce he was able to save the $10,000 for his dream car. The dealer agrees to take the car back for $8000 at the end of 4 years. If the monthly, payment is $400, what is the nominal intrest rate on this loan? What is the effective intrest rate?