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 10 1,500 units): Sales Variable expenses Contribution sargin Fixed expenses Operating Income $ 20,000 12.000 8,000 6.000 5 2,000 13. Using the degree of operating leverage what is the estimated percent increase in operating income of a 5% increase in sales? Increase in operating income %