how to find the constant of proportionality in a fraction?
['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.']