You made an investment of $7,500 into an account that paid you an annual interest rate of 4.1 percent for the first 7 years and 8.5 percent for the next 11 years. What was your annual rate of return over the entire 18 years? Multiple Choice O 7.52 percent O 6.30 percent O 5.41 percent O 6.09 percent O 6.77 percent