The arithmetic mean of a set of data is the simple average calculated by adding up all of the values and dividing by the total number of items.
For example, the arithmetic mean of 4%, 5% and 6% is:
= (4% + 5% + 6%) / 3
= 15% / 3
Also sometimes known more simply as the Mean.
Sometimes denoted by 'µ' - the Greek letter mu (or m).