Elena goes for a long walk. This graph shows her time and distance traveled throughout the walk.

Answer:
4 mph
Step-by-step explanation:
Find the slope of each segment:
from time 0 to time 1, the slope is 3mph
from time 1 to time 1.5, the slope is 0
from time 1.5 to time 2, the slope is 4mph
from time 2 to time 4, the slope is 2mph