Dumbo Corporation has provided the following contribution format income statement. The following information is within the relevant range Sales (3,000 units) Variable expenses Contribution margin Fixed expenses Net operating income $60,000 42,000 18,000 13,200 $ 4,800 Using the degree of operating leverage, the estimated percent increase in net operating income as the result of a 20% increase in sales is closest to: (Round your intermediate calculations to 1 decimal place.) Multiple Choice