Scaling & Similarity
Constant of Proportionality is ratio between two quantities Y and X (k=y/x)
The constant of proportionality and unit rate are the same thing.
If y is directly proportional to x, then the graph of y as a function of x will be a straight line. The constant of proportionality is the slope.
Proportional relationships (Review)
Two variables are proportional if a change in one is always accompanied by a change in the other.