we know that
A relationship between two variables, x, and y, represent a proportional variation if it can be expressed in the form y=kx
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
y=x+4 ------> is not proportional (the line not passes through the origin
y=x/4 ----> is a proportional relationship (the value of k is 1/4)
y=4x ----> is a proportional relationship (the value of k is 4)
y=