Why are there so many different answers when i google university acceptance rates?

You don’t, a statistic means nothing of your chances to get in. By saying you have a eg 1:4 chance of getting in you assume all applications are equal- they are not.
Just because 25% of people might get offers doesn’t mean anything, you don’t know the calibre of applicants and where you stand in that cohort. The best you can do is look at a unis admissions data and see how many offers were given total to the number of applications but again that translates as nothing to do with your personal chances of getting an offer.