Present value) What is the present value of the following future amounts? a. $900 to be received 8 years from now discounted back to the present at 10 percent. b. $400 to be received 8 years from now discounted back to the present at 7 percent. c. $1,000 to be received 11 years from now discounted back to the present at 4 percent. d. $1,100 to be received 6 years from now discounted back to the present at 19 percent