I am in search of the exact formula for calculating 90th percentile value.
Load Runner is using some sorting algos for this. But I am using SilkPerformer and it was using a different formula. Microsoft Excel Function also following that formula (i am getting the same values from excel & SP).
Yes zen! I too cant find a standard formula for this! But i got onething from all the formulas. Everything is giving more or less similar results when the data is very large (say 1000). Even the procedure which uses the sorting algorithm is giving good results. Since 90th percentile is a range and we dont need the exact 90th percentile in decimal places, following the sorting procedure is very simple and time saving.
I am not sure about it... upto my knowledge it is not possible! but we can do it in another way. There is a function call measuregetpercentile. refer that you can get the percentile value of the respective timers using that and its sub-ordiate functions...