PERCENTILE(array,k)
PERCENTILE function returns the k-th percentile of the given data points.
If @array is empty, PERCENTILE returns #NUM! error. If @k < 0 or @k > 1, PERCENTILE returns #NUM! error. This function is Excel compatible.
Let us assume that the cells A1, A2, ..., A5 contain numbers 11.4, 17.3, 21.3, 25.9, and 40.1. Then
PERCENTILE(A1:A5,0.42) equals 20.02.
QUARTILE