The management of Iroquois National Bank is considering an investment in automatic teller machines. The machines would cost $142,600 and have a useful life of seven years. The banks controller has estimated that the automatic teller machines will save the bank $31,000 after taxes during each year of their life (including the depreciation tax shield). The machines will have no salvage value.

Required Compute the payback period for the proposed investment. (Round your answer to 1 decimal place.) Payback period ears