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): $ 10,000 5,500 Sales Variable expenses Contribution margin Fixed expenses Net operating income 4,500 2,250 $ 2,250 a) 1. What is the contribution margin per unit? Contribution margin per unit b) 3. What is the variable expense ratio? Variable expense ratio % C) 5. If sales decline to 900 units, what would be the net operating income? Net operating income d) 7. If the variable cost per unit increases by $1, spending on advertising increases by $1,000, and unit sales increase by 100 units, what would be the net operating income? Net operating income