Answer:
1/4
Step-by-step explanation:
The gravitational potential energy of an object is given by
(1)
where
m is the mass of the object
g is the acceleration of gravity
h is the height relative to the ground
The object in this problem is initially at
h = 100 m
Later, it is found at a position of
h' = 25 m
which is 1/4 of the original position:

We also see from eq.(1) that the potential energy is proportional to h: therefore, if the new potential energy will be

So, 1/4 of the original value.