The term arithmetic mean refers to a central value of a discrete set of numbers. The arithmetic mean of a set of numbers x1, x2, ..., xn is the sum of the sampled values divided by the number of items in the sample.
Formula for Mean : (x1 + x2 + x3 + .... + xn )/ n .
For Example : For a set of values U = {10,20,30,40} mean or average value is the sum of all numbers of U by size of set U. ie. (10 + 20 + 30 + 40) / 4 = 25.
