Answer: <em>Constant of proportionality is the constant value of the ratio between two proportional quantities. Two varying quantities are said to be in a relation of proportionality when, either their ratio or their product yields a constant.</em>
Step-by-step explanation:
To find the constant of proportionality, we use the formula k=y/x. So we have k=20/500 = 0.04.
The equation representing this situation will look like y=kx. Substituting in our value of k that we found, we have the equation y=0.04x.
We can use our equation to find the answer to this problem.
