EXERCISE 3-1 Preparing a Contribution Format Income Statement (L03-11 Whirly Corporation's most recent income statement is shown below: Total Per Unit Sales (10,000 units). Variable expenses Contribution margin.. Fixed expenses... Net operating income. $350,000 200,000 150,000 135,000 $ 15,000 $35.00 20.00 $15.00 Required: Prepare a new contribution format income statement under each of the following conditions (con- sider each case independently): 1. The sales volume increases by 100 units. 2. The sales volume decreases by 100 units. 3. The sales volume is 9,000 units