The internal rate of return method is used by Queen Bros. Construction Co. in analyzing a capital expenditure proposal that involves an investment of $34,554 and annual net cash flows of $6,000 for each of the nine years of its useful life. Present Value of an Annuity of $1 at Compound Interest a. Determine a present value factor for an annuity of $1 which can be used in determining the internal rate of return. If required, round your answer to three decimal places. b. Using the factor determined in part (a) and the present value of an annuity of $1 table above, determine the internal rate of return for the proposal. % Bunker Hill Mining Company has two competing proposals: a processing mill and an electric shovel. Both pieces of equipment have initial investment of $547,255. The net cash flows estimated for the two proposals are as follows: The estimated residual value of the processing mill at the end of Year 4 is $220,000. Determine which equipment should be favored, comparing the net present values of the two proposals and assuming a minimum rate of return of 12%. Use the present value table appearing above