The trimean is computed by adding the 25th percentile plus twice the 50th percentile plus the 75th percentile and dividing by four. What follows is an example of how to compute the trimean. The 25th, 50th, and 75th percentile of the dataset "Example 1" are 51, 55, and 63 respectively. Therefore, the trimean is computed as:

Trimean example

The trimean is almost as resistant to extreme scores as the median and is less subject to sampling fluctuations than the arithmetic mean in extremely skewed distributions. It is less efficient than the mean for normal distributions. . The trimean is a good measure of central tendency and is probably not used as much as it should be.