Whirly Corporation’s contribution format income statement for the most recent month is shown below:

Sales (9,000 units)	$ 306,000	$ 34.00
Variable expenses	171,000	19.00
Contribution margin	135,000	$ 15.00
Fixed expenses	55,100
Net operating income	$ 79,900

Required:

(Consider each case independently):

1. What would be the revised net operating income per month if the sales volume increases by 100 units?

2. What would be the revised net operating income per month if the sales volume decreases by 100 units?

3. What would be the revised net operating income per month if the sales volume is 8,000 units?