A 20 year annuity certain provides payments of $200 at the end of one year, $180 at the end of two years, $160 at the end of 3 three years, and so on until the payments have been reduced to $60. Payments then continue at $60 per year until the 20th payment has been made. The annual effective rate of interest is 4%. Determine the present value of this annuity. 4. .04