What is percentile. I am learning calculating percentiles. Lets say we have 10 numbers 12,23,45,67,7,99,23,12,45,34. If you want to calculate 90th percentile then is it (90/100)*10=9.

So is number 9 greater then 90% of the numbers.

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- Aug 3rd 2008, 12:40 PMhartford27percentile
What is percentile. I am learning calculating percentiles. Lets say we have 10 numbers 12,23,45,67,7,99,23,12,45,34. If you want to calculate 90th percentile then is it (90/100)*10=9.

So is number 9 greater then 90% of the numbers. - Aug 3rd 2008, 08:14 PMCaptainBlack
See the Wikipedia article on percentile

The 90-th percentile for your data is a value that is greater than 90% of the data. First sort your data into ascending order:

7, 12, 12, 23, 23, 34, 45, 45, 67, 99

which because the data is so sparse would strictly be 99. However Excel would calculate this to be 67+0.1*(99-67)=70.2.

Anything above 67 would be a 90-th percentile, but if it has to be a data value it has to be 99.

RonL