Answer:

Explanation:
we know that
A relationship between two variables, x, and y, represent a proportional variation if it can be expressed in the form
or
In a proportional relationship the constant of proportionality k is equal to the slope m of the line and the line passes through the origin
In this problem we have the point (20,4)
Find the value of the constant of proportionality k
For x=20, y=4

substitute

simplify

The equation is equal to
