WorksheetFunction.TrimMean Method

Excel Developer Reference

Returns the mean of the interior of a data set. TRIMMEAN calculates the mean taken by excluding a percentage of data points from the top and bottom tails of a data set. You can use this function when you wish to exclude outlying data from your analysis.

Syntax

expression.TrimMean(Arg1, Arg2)

expression   A variable that represents a WorksheetFunction object.

Parameters

Name Required/Optional Data Type Description
Arg1 Required Variant Array - the array or range of values to trim and average.
Arg2 Required Double Percent - the fractional number of data points to exclude from the calculation. For example, if percent = 0.2, 4 points are trimmed from a data set of 20 points (20 x 0.2): 2 from the top and 2 from the bottom of the set.

Return Value
Double

Remarks

  • If percent < 0 or percent > 1, TRIMMEAN returns the #NUM! error value.
  • TRIMMEAN rounds the number of excluded data points down to the nearest multiple of 2. If percent = 0.1, 10 percent of 30 data points equals 3 points. For symmetry, TRIMMEAN excludes a single value from the top and bottom of the data set.

See Also