Answer:
20 m/km
Explanation:
The average rate of change in elevation with respect to distance along the trail can be calculated using the formula:

From observation of the graph:
- Starting point = (0, 0)
- Point of highest elevation = (6.5, 130)
The change in elevation is the difference between the y-values of the point of highest elevation and the starting point:

The change in distance is the difference between the x-values of the point of highest elevation and the starting point:

Substitute these values into the formula:

Simplifying the division:

So, the average rate of change in elevation with respect to distance along the trail between the starting point and the point of highest elevation is 20 m/km. This means that for every kilometer along the trail, the elevation increases by an average of 20 meters.