The internal rate of retura method is used by Leach Construction Co. in analvzing a capital expenditure proporal that involves an investment of $94,894 and annuit net cash flows of $17,000 for each of the seven years of its useful life. Present Value of an Annuity of $1 at Cammaiua. r-. a. Determine a present vaiue foctor for en annity of 11 which caci be used in determining the internal rate of return. Round your answer to three deciatal places. Present value of an Annuitv of a. Determine a present value factor for an annuity of st which can be used in detormining the intemal rate of return. Round your answer to three decimal piaces. b. Using the factor determived in part (a) and the present waive of an annuitr of 31 tatile above, detemmine the internal rate of teturn for the propocal