The management of Nebraska Corporation is considering the purchase of a new machine costing $$490,000.$ The company's desired rate of return is $10\%.$ The present value factors for $$1$ at compound interest of $10\%$ for $1$ through $5$ years are $0\mathrm{.}909,0\mathrm{.}826,0\mathrm{.}751,0\mathrm{.}683,$ and $0\mathrm{.}621,$ respectively. In addition to the foregoing information, use the following data in determining the acceptability:

Year Operating

Income Net Cash

Flow

$1$ $$100,000$ $$180,000$

$240,000120,000$

$340,000100,000$

$410,00090,000$

$510,000120,000$

The cash payback period for this investment is