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

Total Per Unit

Sales $(8,700$ units$)$ $ $269,700$ $ $31\mathrm{.}00$

Variable expenses $156,60018\mathrm{.}00$

Contribution margin $113,100$ $ $13\mathrm{.}00$

Fixed expenses $54,800$

Net operating income $ $58,300$

Required:

$($Consider each case independently$)$:

$1.$ What would be the revised net operating income per month if the sales volume increases by $90$ units?

$2.$ What would be the revised net operating income per month if the sales volume decreases by $90$ units?

$3.$ What would be the revised net operating income per month if the sales volume is $7,700$ units?