Calculate internal rate of return

Waterway Company is evaluating the purchase of a rebuilt spot-welding machine to be used in the manufacture of a new product. The machine will cost $171,000, has an estimated useful life of 7 years and a salvage value of zero, and will increase net annual cash flows by $35,124. Click here to view the factor table. What is its approximate internal rate of return? (For calculation purposes, use 5 decimal places as displayed in the factor table provided, e.g. 1.25124 and final answers to O decimal places, e.g. 16%.) Internal rate of return %