Scarlett Painting Company is considering whether to purchase a new spray paint machine that costs $2,800. The machine is expected to save labor, increasing net income by $420 per year. The effective life of the machine is 15 years according to the manufacturers estimate.

Required

a.	Determine the unadjusted rate of return based on the average cost of the investment. (Round your final answer to the nearest whole percent.) Unadjusted rate of return=