Exercise 6-6 Examining Cost Behaviour and Contribution Margin (LO1 - CC1, 3; LO2 - CC7; LO3 - CC12) Bikes Manufacturing produces and sells children's bikes at an average price of $80. Its costs are as follows: direct materials, $14, direct labour, $8; variable overhead, $3; sales commission, 10% of price. Its fixed monthly costs are $42,000 Required 1. Using the above cost data, set up a monthly cost equation. Y= 2. What is the company's contribution margin percentage? (Round your answer to 2 decimal places.) Contribution margin