A 20-year annuity pays $1,600 per month, and payments are made at the end of each month. If the interest rate is 11 percent compounded monthly for the first ten years, and 7 percent compounded monthly thereafter, what is the present value of the annuity? (Do not round intermediate calculations and round your final answer to 2 decimal places. (e.g., 32.16)) Please show how you got the answer!!