(Calculating present value) (Related to Checkpoint 5.4 on page 173) What is the present value of the following future amounts?

a. $800 to be received 10 years from now discounted back to the present at 10 percent

b. $300 to be received 5 years from now discounted back to the present at 5 percent

c. $1,000 to be received 8 years from now discounted back to the present at 3 percent

d. $1,000 to be received 8 years from now discounted back to the present at 20 percent