Whirly's contribution format income statement for the most recent month is shown below: Sales (8,400 units) Variable expenses Contribution margin Fixed expenses Operating income Total $294,000 168,000 126,000 111,000 $ 15,000 Per Unit $35.00 20.00 $15.00 Required: Consider each case independently. You need not prepare a new income statement. Instead, use the incremental approach where possible 1. What would be the revised operating income per month of the sales volume increases by 105 units? 2. What would be the revised operating income per month if the sales volume decreases by 200 units? 3. What would be the revised operating income per month if the sales volume is 7400 units