Whirly Corporation's contribution format income statement for the most recent month is shown below: Sales (9,000 units) Variable expenses Contribution margin Fixed expenses Net operating income Total $ 279,000 171,000 108,000 55,500 $ 52,500 Per Unit $31.00 19.00 $ 12.00 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 8,000 units? 1. Revised net operating income 2. Revised net operating income 3. Revised net operating income