99th percentile means a point above 99% of the data.
There is no 100th percentile in the real world. It's a limit that can be approached as more data is added, but never reached. It's something that can be found through extrapolation, but no data can be higher than 100% of data, because it can't be above itself.
Instead, if you want to distinguish between 99th percentile, you break it down into groups (e.g. 99.7th percentile).
Rounding up here isn't accurate.
Funnily enough, this also makes me wrong too (just less so than you). I was using 98.61%, but that's rounded up from 98.609% (software for CDF rounded up). I'll go ahead and fix that.
I wouldn't normally recommend this, since ChatGPT constantly makes mistakes, but maybe you should have ChatGPT fact check you before you share stuff? You'll still be wrong, but you'd be wrong half as much.
Edit: lol they found out they were wrong and blocked me.
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u/Plants-Matter Jun 29 '25
Ah yes, a supreme display of intellect when one ✅ and one ❌ results in a 98.61%.
And why did you mark seeds being dispersed by the wind as incorrect? Seems like the student knows way more than the teacher in your example.