It returns the k-th percentile of values in a range. This function has been replaced by two new functions and you should avoid using it unless it is absolutely necessary. The new functions are PERCENTILE.INC and PERCENTILE.EXC.
PERCENTILE(array,k)
array: Required. The array or range of data that defines relative standing.
k: Required. The percentile value in the range 0..1, inclusive
An empty array or a k<0 or a k>1 return the #NUM! error
If k is nonnumeric, it returns the #VALUE! error value
If k is not a multiple of 1/(n – 1), it interpolates to determine the value at the k-th percentile
Here is an example of how to use the PERCENTILE function:
In the cell B11 calculate the 40th percentile of the cell range B3:M6 .