Applies to: @RISK, all releases

Why does a percentile of the output not equal the sum of that percentile of the inputs?

 

Answer:
This is normal.

In most iterations, some inputs are above a given percentile and some below, so the sum of the inputs at that percentile is usually higher than the output’s percentile.

• Percentiles (and most statistics other than the mean) don’t simply add.
• The realistic measure is the percentile of the total (sum) of outputs, not the sum of input percentiles.
  
  

Attachments:
KB1296_Percentiles.xlsx