MedCalc

# Trimmed Mean functions

TrimMean
TrimMeanSEM

## Description

TrimMean and TrimMeanSEM calculate a trimmed mean and the standard error of a trimmed mean.

TrimMean(k,range) computes the trimmed mean of the contents of the cells in the specified range.

TrimMeanSEM(k,range) computes the standard error of the trimmed mean of the contents of the cells in the specified range.

If k is equal to or larger than 1 then k will be taken as the number of cases to drop at each side (if k=1 then 2 cases will be dropped in total).

If k is smaller than 1 then k will be taken as a proportion and n×k cases will be dropped at each side, so a total of 2×n×k cases will be dropped. For example, if k=0.1 then 10% of cases will be dropped at each side; 20% of cases will be dropped in total).

See Calculation of Trimmed Mean, SE and confidence interval for computational details.

The argument range can be a list of numbers, cell addresses, cell ranges (such as A1:A10).

Range can also be a matrix. In that case the function returns a matrix with one row and the same number of columns, with each element the function of the corresponding column. If Range is a row matrix, it is converted to a column matrix first.

## Examples

TrimMean(0.1,A1:A100) calculates the trimmed mean of the data in range A1:A100 with 10% of cases dropped at each side: 10% at the lower side and 10% at the higher side.

TrimMean(3,A1:A100) calculates the trimmed mean of the data in range A1:A100 with 3 cases dropped at the lower side and 3 cases at the higher side, so a total of 6 cases are dropped.

## Calculator

TrimMean(  ,
TrimMeanLow
TrimMeanHigh

TrimMeanLow and TrimMeanHigh calculate the confidence interval of a trimmed mean.

TrimMeanLow(k,ci,range) and TrimMeanHigh(k,ci,range) compute the lower and higher value of the ci% confidence interval of the trimmed mean of the contents of the cells in the specified range.

The confidence interval ci must be given in the range 0..100. A value of 95 will give the values of a 95% confidence interval.