It is difficult to calculate these values manually and while calculators make it easier, Excel is the preferred tool for finding these values over a range of cells.

How to Calculate a Trimmed Mean in Excel. A trimmed mean is much like a standard mean, which you can derive in Excel using the AVERAGE function. However, instead of using all of the data points to ...

Excel's "trimmean" function calculates the mean of the interior of a data set. You can tailor the function to calculate the interquartile mean.