Sales (10,000 units): $350,000 (total) $35.00 (per unit) Variable expenses: 200,000 (total) $20.00 (per unit) Contribution margin: 150,000 (total) $15.00 (per unit) Fixed expenses are 135,000 Net operating income is $15,000 1. What would be the revised net operating income per month if the sales volume increased by 100 units? 2. What would be the revises net operating income per month if the sales volume decreases by 100 units? 3. What would be the revised net operating income per month if the sales volume is 9,000 units. 4. What is break-even point and why is it important