Julianna Abdallah owns and operates FirstCakes, a bakery that creates personalized birthday cakes for a child's first birthday. The cakes, which sell for $60 and feature an edible picture of the child, are shipped throughout the country. A typical month's results are as follows: $950.400 Sales revenue Variable expenses Contribution margin 712,800 237,600 Fixed expenses 128,400 Operating income $ 109,200 What is FirstCakes' contribution margin ratio? Contribution margin ratio 13.5 %