How much would you have to invest today to receive the following? (Enter all answers as positive numbers.) a. $12,500 in 7 years at 11 percent. (Round your answer to 2 decimal places.) b. $16,100 in 15 years at 10 percent. (Round your answer to 2 decimal places.) c. $6,250 each year for 14 years at 8 percent. (Round your answer to 2 decimal places.)