It took Ryan less time to hike down than it did to hike up. Ernest thinks that was because Ryan jogged down the same trail he went up. Emma thinks the trail down
was steeper than the trail up. Whose hypothesis is valid: Ernest's, Emma's, or both?
Write a detailed explanation of whether each hypothesis is an acceptable
interpretation of the graph.

Both could be correct, but Emma's is more likely.

Step-by-step explanation:

Ernest's hypothesis (jogged down same trail):

This could be accurate, but going based on the fact that his downward time is 4x faster then his upward time. It is safe to say he didn’t jog back down the hill. It is a possibility that this is what happened, but it is less likely and not the more logical conclusion.

Emma's hypothesis (steeper trail):

This seems to be more likely given the compared times, and when looking at the graph. The graph itself kind of maps out the area, not including the break. So this trail is going to be a less steep, but longer climb up, and a much more steep, but much shorter climb down.