How do they find that its between 10% and 11%?

Watertown Paper Corporation is considering adding another machine for the manufacture of corrugated cardboard. The machine would cost $900,000. It would have an estimated life of 6 years and no salvage value. The company estimates that annual cash inflows would increase by $400,000 and that annual cash outflows would increase by $190,000. Management has a required rate of return of 9%. Calculate the internal rate of return on this project and discuss whether it should be acrepted. Now, tina the rate that corrresponas to the PV factor, where n=6 years. In this case, that rate is between 10%&11%; accept project since IRR > req'd rate of return