The constant of proportionality is usually used in stuff regarding to coordinates. It basically is that values increase or decrease proportionally to another value, such as on a graph, say you have a linear equation that gains 4 units up for every 3 units it moves to the right. Those two values are proportional because they'll continue to move at the same predictable rate. The image below is that line. It doesn't just apply to linear equations though, it can apply to other kinds, like exponential or absolute value equations.
Sorry if this wasn't super concise, as this is a really hard topic to explain just over text. However, if it did help a lot, please give me brainliest as I'm trying to rank up. Thanks!
