Whirly Corporation's contribution format income statement for the most recent month is shown below: Sales (8,400 units) Variable expenses Contribution margin Fixed expenses Net operating income Total $ 260,400 151,200 109,200 55,200 $ 54,000 Per Unit $ 31.00 18.00 $ 13.00 Required: (Consider each case independently): 1. What would be the revised net operating income per month if the sales volume increases by 60 units? 2. What would be the revised net operating income per month if the sales volume decreases by 60 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