Whirly Corporation's contribution format income statement for the most recent month is shown below: Total Per Unit Sales (8,600 units) $ 283,800 $ 33.00 Variable expenses 163,400 19.00 Contribution margin 120,400 $ 14.00 Fixed expenses 54,100 Net operating income $ 66,300 Required: (Consider each case independently): What would be the revised net operating income per month if the sales volume increases by 40 units? What would be the revised net operating income per month if the sales volume decreases by 40 units? What would be the revised net operating income per month if the sales volume is 7,600 units