A machine can be purchased for $280,000 and used for 5 years, yielding the following net incomes. In projecting net incomes, double-declining balance depreciation is applied, using a 5-year life and a $50,000 salvage value.
Year 1 Year 2 Year 3 Year 4 Year 5
Net incomes 18,000 48,000 98,000 73,000 198,000
Compute the machine's payback period (ignore taxes)