Check my work Oslo Company prepared the following contribution format income statement based on a sales volume of 1,000 units (the relevant range of production is 500 units to 1,500 units) Sales Variable expenses $ 20,000 12,000 Contribution margin Fixed expenses Net operating income 8,000 6,000 $ 2,000 13. Using the degree of operating leverage, what is the estimated percent increase in net operating income of a 5% increase in sales Increase in net operating incomo earch