Final answer:
The Modified Internal Rate of Return (MIRR) calculates a project's rate of return by incorporating the cost of capital and assuming all negative and positive cash flows over an investment period.
Step-by-step explanation:
The Modified Internal Rate of Return (MIRR) is a financial measure used to assess the attractiveness of an investment by evaluating the time value of money and incorporating the cost of capital.
In this case, with a firm's cost of capital at 12%, the MIRR is calculated based on the project's expected cash flows over eight years, which include both positive and negative amounts.
The MIRR is found using financial functions or a financial calculator, which cumulate cash outflows at the cost of capital rate and future cash inflows at the reinvestment rate till the end of the project to derive a single rate that discounts all cash flows to a net present value of zero.