A company is considering purchasing factory equipment that costs $600000 and is estimated to have no salvage value at the end of its 8-year useful life. If the equipment is purchased annual revenues are expected to be $135000 and annual operating expenses exclusive of depreciation expense are expected to be $39000. The straight-line method of depreciation would be used. The cash payback period on the equipment i is 28.6 years. 8.0 years. 6.3 years 3.2 years