Whirly's contribution format income statement for the most recent month is shown below: Sales (9,400 units) Variable expenses Contribution margin Fixed expenses Operating income Total S423,800 141, Bee 282,000 252,000 530, Per Unit $45.ee 15.ee $3e.ee 52 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 if the sales volume increases by 90 units? 2. What would be the revised operating income per month if the sales volume decreases by 190 units? 3. What would be the revised operating Income per month if the sales volume is 8.400 units? 1. Revised operating income 2. Revised operating income 3. Revised operating income