Calculate percentile for larger time period from list of percentile values

[hiver22]

Hi. I'm not so good with statistics, at first sight problem is not resolvable. But i thought maybe there is some method/formula.

Problem: every day i calculate percentile for metric. So, in the end of week i have list of 7 values.
Is it possible to calculate weekly percentile value from this list? I know, we dont have all values needed for exact calculation, but maybe there is some method which can help?

 

[Dr.Peterson]

You haven't indicated what sort of value this is a percentile of. Is this something that adds up each day, and each day you are told what percentile your value is within some population that is also adding up each day? Or is your percentile measured relative to some static population?

That may make a difference, though you're probably right that it can't be done accurately without more information. It sounds like you do have more information, if you calculate this percentile yourself!

 

[hiver22]

Thanks for response. Basically, each day i have new list of values and calculate percentile of this list. But in the end of week i dont have all daily values, i have only 7 daily percentiles instead

 

[Dr.Peterson]

I don't think there is any way you can combine these percentiles to obtain a reasonable overall percentile, because the population within which the percentile is defined can be changing in unpredictable ways. You could have the same value yourself every day, while the percentile changes because the population changes. With no knowledge of changes in the population, you can't say what the "average" is.