Please assist in explanation of formulas used to solve the below questions:

In addition to your solution to each computational problem, you must show the supporting work leading to your solution to receive credit for your answer.

1. If interest rates are 8 percent, what is the future value of a $400 annuity payment over six years? Unless otherwise directed, assume annual compounding periods.

• Recalculate the future value at 6 percent interest and 9 percent interest.

1. If interest rates are 5 percent, what is the present value of a $900 annuity payment over three years? Unless otherwise directed, assume annual compounding periods.

• Recalculate the present value at 10 percent interest and 13 percent interest.

1. What is the present value of a series of $1150 payments made every year for 14 years when the discount rate is 9 percent?

• Recalculate the present value using discount rate of 11 percent and 12 percent.