Rooney Painting Company is considering whether to purchase a new spray paint machine that costs $5,800. The machine is expected to save labot, increasing net income by $1160 per year. The effective life of the machine ls 15 years according to the manufacturer's estimate. Required a. Determine the unadjusted rate of return based on the average cost of the investment. (Enter your answer as a whole percentage (e.g. 0.55 should be entered as 55).) %