Answer:
Non-proportional; the rate of change is $40/hour
Step-by-step 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 <u>and the line passes through the origin</u>
Let
x -----> the number of hours
y ----> The total charge in dollars
The equation of the line in slope intercept form is equal to

where
m is the slope
b is the y-intercept
we have

substitute

This relationship is not proportional, because the line not passes through the origin
therefore
Non-proportional; the rate of change is $40/hour