When I calculate position measures like percentiles from a data base, excel returns values with decimals that have nothing to do with the accurate result.
For example, in the image I attach, I'm signaling the results of the percentiles I want, but in the case of the Decile 8/ Percentile 80, the result should be 9.5, as it is the result of the average of 9.1 and 9.9, but excel returns 9.26 ??? And I don't understand where does it get that from. Same happens with the other results.
I would really appreciate if someone could help me.