Assume you make the following investments: a. You invest a lump sum of $7,750 for three years at 12% interest. What is the investment's value at the end of three years? b. In a different account earning 12% interest, you invest $2,583 at the end of each year for three years. What is the investment's value at the end of three years? What general rule of thumb explains the difference in the investments' future values? 3 (Click the icon to view the future value factor table.) (Click the icon to view the future value annuity factor table.) (Click the icon to view the present value factor table.) (Click the icon to view the present value annuity factor table.) C. a. You invest a lump sum of $7,750 for three years at 12% interest. What is the investment's value at the end of three years? (Round your answer to the nearest whole dollar.) Investment's value =