CHAPTER 9 B-163
b. The equation for the IRR of the project is:
0 = –$45,000,000 + $78,000,000/(1+IRR) – $14,000,000/(1+IRR)2
From Descartes rule of signs, we know there are potentially two IRRs since the cash flows change
signs twice. From trial and error, the two IRRs are:
IRR = 53.00%, –79.67%
When there are multiple IRRs, the IRR decision rule is ambiguous. Both IRRs are correct, that is,
both interest rates make the NPV of the project equal to zero. If we are evaluating whether or not
to accept this project, we would not want to use the IRR to make our decision.
15. The profitability index is defined as the PV of the cash inflows divided by the PV of the cash outflows.
The equation for the profitability index at a required return of 10 percent is:
PI = [$7,300/1.1 + $6,900/1.12 + $5,700/1.13] / $14,000 = 1.187
The equation for the profitability index at a required return of 15 percent is:
PI = [$7,300/1.15 + $6,900/1.152 + $5,700/1.153] / $14,000 = 1.094
The equation for the profitability index at a required return of 22 percent is:
PI = [$7,300/1.22 + $6,900/1.222 + $5,700/1.223] / $14,000 = 0.983
We would accept the project if the required return were 10 percent or 15 percent since the PI is greater
than one. We would reject the project if the required return were 22 percent since the PI is less than one.
16. a. The profitability index is the PV of the future cash flows divided by the initial investment. The cash
flows for both projects are an annuity, so:
b. The NPV of each project is:
NPVI = –$53,000 + $27,000(PVIFA10%,3) = $14,145.00