When something is proportional to something else, it does not mean the values are equal, just that they change with respect to eachother. The constant of proportionality serves as a multiplier.

Is proportional the same as equal?

As adjectives the difference between proportional and equal

is that proportional is at a constant ratio (to) two magnitudes (numbers) are said to be proportional if the second varies in a direct relation arithmetically to the first while equal is (label) the same in all respects.

Does a proportional relationship have to be equal?

Proportional relationships are relationships between two variables where their ratios are equivalent.