» Excluding Exceptional Values when Calculating an Average

Problem:

List1 (column A) contains 10 numbers, two of which (0 & 500) are significantly smaller or greater than the remainder.
If included in an average calculation, these exceptional values would disproportionately influence the result.
We, therefore, need a way of calculating an average that more accurately reflects the general spread of data.

Solution:

Use the TRIMMEAN function as shown in the following formula:
=TRIMMEAN(A2:A11,0.2)