21- Petra Co is evaluating an investment that requires a $1,125,000 and 8 years life. The salvage value of the required investment is 0. The net operating income will be as follows for the life of the project: Sales $650,000 Less cash variable expenses .230,000 Contribution margin..... 420,000 Less fixed expenses: Fixed cash expenses.. $170,000 Depreciation expenses... ...32,500 202.500 Net operating income.. $217,500 The company's required rate of return is 12%. The payback period for this project is closest to (Ignore income taxes in this problem)