The grade of a hill is its steepness represented as a percent. Jin tracks his walking speed up different hills. What does the rate of change, or slope, represent?

Question

The grade of a hill is its steepness represented as a percent. Jin tracks his walking speed up different hills. What does the rate of change, or slope, represent?

A scatterplot with grade of hill as a percent on the X axis and walking speed in miles per hour on the Y axis. There are several dots plotted close together that follow a fairly diagonal path that falls from left to right, along with the line Y equals negative 1-fourth X plotted through the approximate center of the points.
the rate represents an either increase or decrease in walking
speed of 1 mph for each increase of 1/4% or 4% in the grade of the hill

Answer 1

This means that for every 1% increase in the grade of the hill, Jin's walking speed decreases by 0.25 miles per hour. This relationship is represented by the slope of the line, which is -1/4.