Excel TRIMMEAN function

Function              TRIMMEAN

Description        Excel TRIMMEAN function calculates the trimmed mean of a supplied set of values.

Syntax     TRIMMEAN( array, percent )

array      An array of numeric values, of which trimmed mean to calculate.

percent    The percentage of values which to be trimmed from the supplied array.

Example:

Usage Notes:

• A percentage of 10%, is 1 values, which will be rounded down to 0. A percentage of 20% and 30%, is 2 and 3 values, which will be rounded down to 2. A percentage of 40% and 50%, is 4 and 5 values, which will be rounded down to 4.
• If percentage < 0 or percentage > 1, TRIMMEAN returns the #NUM! error value.