Final answer:
The fourth statement and reason in the proof represents the segment addition, which states that EG is equal to EF plus FG.
Step-by-step explanation:
The fourth statement and reason in the proof represents the segment addition. It states that EG is equal to EF plus FG. This step uses the segment addition property, which states that if you have three points on a line, the distance between the first and third point is equal to the sum of the distances between the first and second point and the second and third point.