You want to borrow 20,000 dollars for two years. The interest is 8 percent a year. You and lender agree that the interest on the $20,000 will be $3200 for two years. So, the lender deducts this amount from the loan and gives you $16,800. You repay the $20,000 in two years, thereby paying 3,200 interest as agreed. What is the effective annual interest rate?