84/91 as a percentage is 92.31%. This number shows how close the fraction is to a whole one, since it is just a little under 100 %.
The fraction 84/91 can be thought of as 84 parts out of a total of 91 equal parts. Because the numerator is only 7 less than the denominator, the value is high, which matches the 92.31 % result.
In everyday situations, a percentage like 92.31% might represent a test score, a success rate, or the amount of something that’s been completed. It’s a quick way to see that most of the whole is present, but not quite all of it.