You are considering buying a $50,000 car. The dealer has offered you a 13.6 percent loan with 30 equal monthly payments. On questioning him, you find that the interest charge of $17,000 (or .136*$50000*2.5 years) is added to the $50000 for a total amount of 67000. The payments are $2233.33 a month. What is the approximate effective annual interest rate?