A company is considering the purchase of a new machine for $57,000. Management predicts that the machine can produce sales of $16,900 each year for the next 10 years. Expenses are expected to include direct materials, direct labor, and factory overhead totaling $7,100 per year including depreciation of $4,900 per year. Income tax expense is $3,920 per year based on a tax rate of 40%. What is the payback period for the new machine?