Find the present value of $800 due in the future under each of these conditions: a. 4% nominal rate, semiannual compounding, discounted back 7 years. Do not round Intermediate calculations. Round your answer to the nearest cent. $ b. 4% nominal rate, quarterly compounding, discounted back 7 years. Do not round intermediate calculations. Round your answer to the nearest cent. $ c.4% nominal rate, monthly compounding, discounted back 1 year. Do not round intermediate calculations. Round your answer to the nearest cent. $ d. Why do the differences in the PVs occur? -Select