The following present value factors are provided for use in this problem. Periods Present Value of $1 at 9% 0.9174 0.8417 0.7722 0.7084 Present Value of an Annuity of $1 at 9% 0.9174 1.7591 2.5313 3.2397 Cliff Co. wants to purchase a machine for $56,000, but needs to earn a return of 9%. The expected year-end net cash flows are $21,000 in each of the first three years, and $25,000 in the fourth year. What is the machine's net present value