Ben is making payments of $391 at the end of each month for 12 years to pay off a $49,568 medical procedure that he currently owes. What interest rate is Ben paying if he makes his first payment at the end of this month?

Answer Format: INCLUDE ONLY NUMBERS AND DECIMALS IN YOUR ANSWER. Do not include "$" "," or any other formatting. Carry interim computations to at least 4 decimals. Enter percentage answers as a positive percentage % rounded to 2 decimal places. For example 0.123456 should be enter as: 12.35 (##.##)