Sheridan Inc. is considering modernizing its production facility by investing in new equipment and selling the old equipment. The following information has been collected on this investment: Depreciation is $10,000 per year for the old equipment. The straight-line depreciation method would be used for the new equipment over an eight-year period with salvage value of $4,400. (a) Determine the cash payback period. (Ignore income taxes.) (Round answer to 3 decimal places, eg. 15.275.)