If Money Earns 7

Short Answer

If money earns 7.5%, calculate and compare the economic value today of the following payment streams:
a) Payments of $1,800 and $2,800 made 150 and 90 days ago, respectively.
b) Payments of $1,600, $1,200, and $2,000 due 30, 75, and 120 days from now, respectively.