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): Required: 3. What is the variable expense ratio? 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): Required: 4. If sales increase to 1,001 units, what would be the increase in net operating income? Note: Round your answer to 2 decimal places. 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 fange of production is 500 units to 1,500 units): Required: 5. If sales decline to 900 units, what would be the net operating income? Note: Round "Per Unit" calculations to 2 decimal places