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. $8,100 in 6 years at 11 percent? (Do not round intermediate calculations. Round your final answer to 2 decimal places.) b. $18,100 in 3 years at 6 percent? (Do not round intermediate calculations. Round your final answer to 2 decimal places.) c. $27,800 in 9 years at 8 percent? (Do not round intermediate calculations. Round your final answer to 2 decimal places.)