22.73% is what you get when you turn 15/66 into a percentage. It’s a quick way to see how big the fraction is compared to a whole.
The fraction 15/66 can be reduced to 5/22, but the size stays the same. Whether you write it as 15/66, 5/22, or 22.73%, the value doesn’t change—it’s just a different way to show the same part of a whole.
Knowing the percentage helps when you compare it to other numbers. For example, if 22.73% of a class of 100 students likes pizza, about 23 students would be the fans. Using percentages makes such comparisons easy and clear.