To find the slope of the linear graph that represents the parking fees, we can use the two points given: (2, 20) and (6, 44).
The formula for the slope (m) between two points \((x_1, y_1)\) and \((x_2, y_2)\) is:
\[ m = \frac{y_2 - y_1}{x_2 - x_1} \]
Plugging in the coordinates of the points:
\[ x_1 = 2, y_1 = 20 \] \[ x_2 = 6, y_2 = 44 \]
The slope can be calculated as follows:
\[ m = \frac{44 - 20}{6 - 2} = \frac{24}{4} = 6 \]
This means that the slope of the graph is 6.
Thus, the interpretation of the slope is: The parking fee rises by $6 with each additional hour.
So, the correct response is:
The parking fee rises by $6 with each additional hour.