Required Information The following information applies to the questions displayed below.) 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 Contribution margin Fixed expenses Net operating income $80,000 52,000 28,000 21,840 $ 6,160 13. Using the degree of operating leverage, what is the estimated percent Increase in net operating Income of a 5% Increase in sales? (Round your Intermediate calculations and final answer to 2 decimal places.) Increase in net operating income