What is the present value of the following? Use Appendix B as an approximate answer, but calculate your final answer using the formula and financial calculator methods. a. $8,000 in 13 years at 8 percent? Note: Do not round intermediate calculations. Round your final answer to 2 decimal places. Present value b. $18,000 in 7 years at 9 percent? Note: Do not round intermediate calculations. Round your final answer to 2 decimal places. c. $27,800 in 18 years at 10 percent? Note: Do not round intermediate calculations. Round your final answer to 2 decimal places