The correct response is:
3 inches rise for every foot in length
Explanation:
To derive the rate of change, we need to compute the difference in height and the difference in distance. The rate of change is expressed as rise/run, or
(change in height)/(change in length).
The respective heights at the specified points are 18 inches and 12 inches, resulting in a change of 18-12 = 6 inches.
The corresponding lengths at those points are 6 feet and 4 feet, yielding a change of 6-4 = 2 feet.
This implies our rate of change is (6 inches)/(2 feet), which simplifies to (3 inches)/(1 foot), indicating a rise of 3 inches for each foot of incline on the driveway.