Module 7 (M7) proportion and variation is concerned with direct proportion between two variables. For inverse proportion, one quantity decreases as the other increases. For example, if speed is ...

There is a direct proportion between two values when one is a multiple of the other. For example, \(1\text{cm} = 10\text{mm}.\) To convert \(\text{cm}\) to \(\text{mm}\), the multiplier is always 10.