If you have a collection of numbers in an array, then =PERCENTILE(array,0.9)
will give you the value below which 90% of the numbers in the array lie, so
only 10% of the population are above that value.

See http://www.itl.nist.gov/div898/handb...on2/prc252.htm for one
of many simple introductory tutorials which you can find on the web.
--
David Biddulph

"MikeR-Oz" wrote in message
...
Thanks, but I really am trying to undersatnd what the percentile does -
what
it sais about data, so as to decide whether I want that analysis. Can you
explain the way it works and what it sais and why you might use it?

Mike

"fascal" wrote:

Returns the k-th percentile of values in a range. You can use this
function
to establish a threshold of acceptance. For example, you can decide to
examine candidates who score above the 90th percentile.

Syntax

PERCENTILE(array,k)

Array is the array or range of data that defines relative standing.

K is the percentile value in the range 0..1, inclusive.

Remarks

If array is empty or contains more than 8,191 data points, PERCENTILE
returns the #NUM! error value.
If k is nonnumeric, PERCENTILE returns the #VALUE! error value.
If k is < 0 or if k 1, PERCENTILE returns the #NUM! error value.
If k is not a multiple of 1/(n - 1), PERCENTILE interpolates to determine
the value at the k-th percentile.


"MikeR-Oz" wrote:

I have a list of numbers that represents numbers of peole that attend
the
store at various times of the day e.g 4 at 8 am ,9 at 11 am ...3 at 7pm
etc
and this is expressed on a graph as the averages for these times of
days and
the 90th percentile.

Whats this meaning.

Thanks
Mike