Using proportions, it is found that Mark will run 8.52 miles before he gets to the foot of the hill.
A proportion is a fraction of a total amount.
In this problem, the distance to the foot of the hill is 65% of 13.1 miles, hence:
d = 0.65 x 13.1 = 8.52 miles.
Mark will run 8.52 miles before he gets to the foot of the hill.
More can be learned about proportions at https://brainly.com/question/24372153