[ The follow 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 $ 85 , 000 Variable expenses 59 , 500 Contribution margin 25, 500 Fixed expenses 20, 400 Net operating income $ 5, 100 Required: 3. What is the variable expense ratio? Variable expense ratio %