A machine can be purchased for $90,000 and used for five years, yielding the following net incomes. In projecting net incomes, straight-line depreciation is applied, using a five-year life and a zero salvage value.

	Year 1				Year 2				Year 3				Year 4				Year 5
Net income		$	6,000			$	15,000			$	36,000			$	22,500			$	60,000

Compute the machines payback period (ignore taxes). (Round payback period answer to 4 decimal places.)