17/25 expressed as a percentage is 68.00%. This rounded figure shows how much of a whole the fraction represents when turned into a percent.
The fraction 17/25 can be thought of as 17 parts out of 25 equal parts. When you compare those parts to a full set of 100, you get the same proportion, which is the 68.00% you see above.
In everyday situations, you might use this percentage to describe a score, a discount, or any measurement where you need to relate a part to a whole in a clear, familiar way.