Manuals/calci/TRIMMEAN

TRIMMEAN(ar,p)

Description

This function gives the truncated mean of a given set of points.
Trimmean is a measure of mean that indicates the central tendancy of a set of values.
Trimmean is also called truncated mean.
It is the method of finding average that removes a small percentage of the largest and smallest values before calculating the mean.
In $TRIMMEAN(ar,p)ar$ is the array of values to calculate the trimmed mean.p is the fractional number that we want to remove from the given set of numbers.
For e.g., if p=0.2 for the 20 points data set, then to calculate the $TRIMMEAN$ it will exclude 4 points(20*0.2) from the data set, 2 numbers from lowest value and 2 numbers from highest value.
Also this function rounds the number of excluded data points down to the nearset multiple of 2.
If p=0.1 for the 30 points data set, then it should exclude (30*0.1) 3 points from the data set. But it will remove one number from top and one number from bottom, so it will exclude only 2 numbers instead of 3 numbers.

      This function will give the result as error when p<0 or p>1

Spreadsheet
	A	B	C	D	E	F	G	H	I	J	K	L
1	14	18	21	19	20	23	8	10	7	18	12	11