Calculate the future value of $2,000 in a. Four years at an interest rate of 10% per year. b. Eight years at an interest rate of 10% per year c. Four years at an interest rate of 20% per year. d. Why is the amount of interest eared in part (a) less than half the amount of interest earned in part (b)? b. Eight years at an interest rate of 10% per year. The future value of $2,000 in 8 years at an interest rate of 10% per year is $ (Round to the nearest dollar)