King High School has asked Carter to paint some murals around the school, and Carter is thrilled! His mural in the main office will show a ray of sunlight breaking through storm clouds. Carter creates the perfect gray for storm clouds. There is a proportional relationship between the number of cans of black paint, x, and the number of cans of white paint, y, Carter mixes together.
x (cans of black paint) y (cans of white paint)
1 2
2 4
4 8
5 10
What is the constant of proportionality? Write your answer as a whole number or decimal.
cans of white paint per can of black paint