Calculate the future value of $10,000 in a. 4 years at an interest rate of 7% per year. b. 8 years at an interest rate of 7% per year. c. 4 years at an interest rate of 14% per year. d. Why is the amount of interest earned in part a less than half the amount of interest earned in part b? a. 4 years at an interest rate of 7% per year. The future value of $10,000 in 4 years at an interest rate of 7% per year is $ (Round to the nearest dollar.)