How much would you have to invest today to receive the following? Use Appendix B and Appendix D for an approximate answer, but calculate your final answer using the formula and financial calculator methods.

a. $13,600 in 11 years at 8 percent. (Do not round intermediate calculations. Round your final answer to 2 decimal places.)

b. $17,500 in 17 years at 13 percent. (Do not round intermediate calculations. Round your final answer to 2 decimal places.)

c. $7,000 each year for 20 years at 8 percent. (Do not round intermediate calculations. Round your final answer to 2 decimal places.)

d. $47,000 each year for 50 years at 17 percent. (Do not round intermediate calculations. Round your final answer to 2 decimal places.)