Which statement about proportional relationships is false?

A proportional relationship has a constant ratio between corresponding values, so its graph is a straight line that passes through (0, 0). The differences between values do not have to stay the same; for example, in y = 2x, when x increases by 1, y increases by 2, but other proportional relationships can have different rates. Therefore, the false statement is that each pair must share the same difference.

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