An investment offers $6,400 per year, with the first payment occurring one year from now. The required return is 6 percent. a. What would the value be today if the payments occurred for 15 years? (Do not round intermediate calculations and round your answer to 2 decimal places, e.g., 32.16.) b. What would the value be today if the payments occurred for 40 years? (Do not round intermediate calculations and round your answer to 2 decimal places, e.g., 32.16.) c. What would the value be today if the payments occurred for 75 years? (Do not round intermediate calculations and round your answer to 2 decimal places, e.g., 32.16.) d. What would the value be today if the payments occurred forever? (Do not round intermediate calculations and round your answer to 2 decimal places, e.g., 32.16.)