Final answer:
To find the length of the walkathon, we need to multiply the fraction of the walk completed by the distance at that point. In this case, the volunteers were 3/4 finished when they reached the 4 1/2 kilometer mark, so the length of the walkathon is 3 3/8 kilometers.
Step-by-step explanation:
To find the length of the walkathon, we need to determine how long the volunteers have already walked. We know that they were 3/4 finished when they reached the 4 1/2 kilometer mark.
To find this distance, we can multiply 4 1/2 by 3/4:
(4 1/2) x (3/4) = (9/2) x (3/4) = 27/8 = 3 3/8 kilometers
Therefore, the length of the walkathon is 3 3/8 kilometers.