Here, we have cash flows that would have occurred in the past and cash flows that would occur in the
future. We need to bring both cash flows to today. Before we calculate the value of the cash flows
today, we must adjust the interest rate, so we have the effective monthly interest rate. Finding the APR
with monthly compounding and dividing by 12 will give us the effective monthly rate. The APR with
monthly compounding is:
APR = 12[(1.09)1/12 – 1] = 8.65%
To find the value today of the back pay from two years ago, we will find the FV of the annuity (salary),
and then find the FV of the lump sum value of the salary. Doing so gives us:
FV = ($42,000/12)[{[1 + (.0865/12)]12 – 1}/(.0865/12)](1 + .09) = $47,639.05
Notice we found the FV of the annuity with the effective monthly rate, and then found the FV of the
lump sum with the EAR. Alternatively, we could have found the FV of the lump sum with the effective
monthly rate as long as we used 12 periods. The answer would be the same either way.
Now, we need to find the value today of last year’s back pay:
FVA = ($45,000/12)[{[1 + (.0865/12)]12 – 1}/(.0865/12)] = $46,827.37
Next, we find the value today of the five year’s future salary:
PVA = ($49,000/12){[{1 – {1/[1 + (.0865/12)]12(5)}]/(.0865/12)} = $198,332.55
The value today of the jury award is the sum of salaries, plus the compensation for pain and suffering,
and court costs. The award should be for the amount of:
Award = $47,639.05 + 46,827.37 + 198,332.55 + 150,000 + 25,000
Award = $467,798.97
As the plaintiff, you would prefer a lower interest rate. In this problem, we are calculating both the PV
and FV of annuities. A lower interest rate will decrease the FVA, but increase the PVA. So, by a lower
interest rate, we are lowering the value of the back pay. But, we are also increasing the PV of the future
salary. Since the future salary is larger and has a longer time, this is the more important cash flow to
the plaintiff.
64. To find the interest rate of a loan, we need to look at the cash flows of the loan. Since this loan is in