Internal Rate of Return Method The internal rate of return method is used by Testeman Construction CD, in analyzing a capital expenditure proposal that involves an investment of $84,240 and annual net cash flows of $20,000 for each of the five years of its useful life. Present Value of an Annuity of $1 at Compound Interest a. Determine a present value factor for an annulty of $1 which can be used in determining the intermal rate of return. If required, round your answer to three decimal places. b. Using the factor determined in part (a) and the pretent value of an annuity of 51 table above, determine the internal rate of return for the proposal