Whirly Corporations contribution format income statement for the most recent month is shown below: Total Per Unit Sales (8,900 units) $ 284,800 $ 32.00 Variable expenses 178,000 20.00 Contribution margin 106,800 $ 12.00 Fixed expenses 55,500 Net operating income $ 51,300 Required: (Consider each case independently): What would be the revised net operating income per month if the sales volume increases by 70 units? What would be the revised net operating income per month if the sales volume decreases by 70 units? What would be the revised net operating income per month if the sales volume is 7,900 units?