Solution Introduction: Return on Investment (ROI) is the measure to determine the returns in terms of percentage a specific investment or money input provides to the investor. Solution: Return on Investment = Profit on Investment / Net Investment * 100 Here, Profit on Investement = Net operating income = $108,000 Net Investment = Average operating assets = $720,000 Return on Investment = $108,000 / $720,000 * 100 = 15% . .