How much would you have to invest today to receive the following? Use Appendix B or Appendix D for an approximate answer, but calculate your final answer using the formula and financial calculator methods. a. $13,000 in 8 years at 12 percent. (Do not round intermediate calculations. Round your final answer to 2 decimal places.) b. $16,500 in 15 years at 9 percent. (Do not round intermediate calculations. Round your final answer to 2 decimal places.) c. $6,700 each year for 17 years at 15 percent. (Do not round intermediate calculations. Round your final answer to 2 decimal places.) d. $44,000 each year for 40 years at 9 percent. (Do not round intermediate calculations. Round your final answer to 2 decimal places.)