Dunkin lab plans to purchase a new centrifuge machine for its Arizona facility. The machine costs $567,000 and is expected to have a useful life of 8 years, with a terminal disposal value of $54,000. Savings in cash operating costs are expected to be $108,000 per year. However, additional working capital is needed to keep the machine running efficiently. The working capital must continually be replaced, so an investment of $38,000 needs to be maintained at all times, but this investment is fully recoverable (will be "cashed in") at the end of the useful life. Dunkin Lab's required rate of return is 8%. Ignore income taxes in your analysis. Assume all cash flows occur at year-end except for initial investment amounts. Dunkin Lab uses straight-line depreciation for its machines.

I calculated the the NPV to be $65356. (which is correct).

I need help with how to solve for the Initital rate of return (IRR). It states (Use a trial-and-error approach and straight-line interpolation as necessary. Round all present value calculations to the nearest whole dollar and round the IRR to two decimal places, X.XX%.)

If it can just be done with a financial calculator, the steps to do that would be helpful also.Thanks!