Answer:
44 %
Explanation:
Hi your question is incomplete, I have searched for the full question online and I have attached it as an image below.
Contribution margin ratio = Contribution / Sales  x 100
where
Contribution = Sales - Variable Costs
           = $21.58 - $12.00
           = $9.58
therefore,
Contribution margin ratio = $9.58 / $21.58 x 100
                     = 44.39 %