You have an outstanding student loan with required payments of $600 per month for the next four years. The interest on the loan is 9% APR (monthly). You are considering making an extra payment of $100 today (that is, you will pay ar extra $100 that you are not required to pay). If you are required to continue to make payments of $600 per month until the loan is paid off , what is the amount of your final payment? What effective rate of return (expressed as an APR with monthly compounding) have you earned on the $100