73.00% is the percentage equivalent of the fraction 73/100.
The fraction 73/100 means you have 73 parts out of a total of 100 equal parts. When you think of a whole as 100%, each part represents one percent, so 73 parts become 73 percent. Written with two decimal places, it appears as 73.00%.
This kind of conversion is handy in everyday situations—like seeing a test score of 73 out of 100, which you can instantly read as a 73.00% grade. It also makes it easier to compare numbers, because percentages are a common language for expressing parts of a whole.