This problem demonstrates the dependence of an annuitys present value on the compounding frequency. What minimum initial amount will sustain a 25-year annuity paying $1,000 at the end of each year if the initial amount can be invested to earn: (Do not round intermediate calculations and round your final answer to 2 decimal places.) a. 6% compounded annually? $ b. 6% compounded semiannually? $ c. 6% compounded quarterly? $ d. 6% compounded monthly? $