Whirly corporation’s contribution format income statement for the most recent month is shown below: total per unit sales (7,800 units) $ 273,000 $ 35.00 variable expenses 140,400 18.00 contribution margin 132,600 $ 17.00 fixed expenses 55,700 net operating income $ 76,900 required: (consider each case independently): 1. what would be the revised net operating income per month if the sales volume increases by 40 units? 2. what would be the revised net operating income per month if the sales volume decreases by 40 units? 3. what would be the revised net operating income per month if the sales volume is 6,800 units?