Whirly Corporation's contribution format income statement for the most recent month is shown below: Sales (8,400 units) Contribution margin Variable expenses Total $ 268,800 168,000 100,800 Per Unit $ 32.00 20.00 $ 12.00 Fixed expenses 55,500 Net operating income $ 45,300 Required: (Consider each case independently): 1. What would be the revised net operating income per month if the sales volume increases by 80 units? 2. What would be the revised net operating income per month if the sales volume decreases by 80 units? 3. What would be the revised net operating income per month if the sales volume is 7,400 units? 1. Revised net operating income 2. Revised net operating income 3. Revised net operating income