Find the present value of $500 due in the future under each of these conditions: a. 6% nominal rate, semiannual compounding, discounted back 4 years. Do not round intermediate calculations. Round your answer to the nearest cent. b. 6% nominal rate, quarterly compounding, disceunted back 4 years. Do not round intermediate calculations, Round your answer to the nearest cent. 3 c. 6% nominal rate, monthly compounding, discounted back 1 yeac, Do not round intermediate cakculations. Round your answer to the nearest cent. d. Why do the differences in the PVis occun