Answer
The answer and procedures of the exercise are attached in the following archives.
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<em>You didn´t post the complete information of the exercise, I searched the exercise online and tried to ask the most useful question.</em>
Explanation
You will find the procedures, formulas or necessary explanations in the archive attached below. If you have any question ask and I will aclare your doubts kindly.
The contribution margin approach helps managers in short-tern decision making because it reports costs and revenues at their current value.
The contribution margin ratio/approach allows companies to determine their profits they can make from a product minus variable costs.