Answer:
5.425 feet.
Explanation:
We have been given that Cece is hiking on a mountain and stops 15 5/8 feet above sea level the base of the mountain is 10.2 feet above sea level.
First of all, we will convert 15 5/8 to decimal as:

To find the vertical distance between Cece and the base of the mountain, we will subtract 10.2 feet from 15.625 feet.

Therefore, the distance between Cece and the base of the mountain is 5.425 feet.