An anticipated purchase of equipment for $520,000, with a useful life of 8 years and no residual value, is expected to yield the following annual net incomes and net cash flows:

Year	Net Income	Net Cash Flow
1	$60,000	$90,000
2	50,000	110,000
3	50,000	110,000
4	72,000	100,000
5	72,000	55,000
6	72,000	55,000
7	72,000	40,000
8	72,000	40,000

What is the cash payback period?

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