Question

How do you know if a relationship between two quantities is NOT proportional?​

Answer 1

Just divide y by x for every single term, and if they get the same quotient, they are proportional.

For example:

x y

2 4 Divide 4/2. This equals 2.

6 12 Divide 12/6. This equals 2.

4 8 Divide 8/4. This equals 2.

Therefore, these quantities are proportional.