$2.$ Whirly Corporation$$s contribution format income statement for the most recent month is shown below:

Total Per Unit

Sales $(7,200$ units$)$ $$244,800$ $$34\mathrm{.}00$

Variable expenses $136,80019\mathrm{.}00$

Contribution margin $108,000$ $ $15\mathrm{.}00$

Fixed expenses $54,900$

Net operating income $$53,100$

Required:

a$)$ What would be the revised net operating income per month if the sales volume increases by $70$ units?

b$)$ What would be the revised net operating income per month if the sales volume decreases by $70$ units?

c$)$ What would be the revised net operating income per month if the sales volume is $6,200$ units?