Arithmetic Mean (A.M)

The arithmetic mean, also popularly referred to as the ‘mean’ is the average of a series of figures or values.

It is obtained by dividing the sum of the figures by the total number of the figures or values.

Formula for calculating Arithmetic Mean

Arithmetic mean (Ẍ) = ∑X/n

Where X = arithmetic mean

∑ = ‘sigma’ which means ’sum of’

X = series of figures in a given data

∑x = the total of the values of series of figures in a given data

N = number of figures or elements


Arithemetic mean
Arithemetic mean2

Mean Deviation:


  1. Arithmetic mean is very easy to calculate
  2. It gives an exact value
  3. It is the best known average
  4. It is very easy to understand
  5. It provides a good market of comparing values
  6. It makes use of all available information


  1. Arithmetic mean cannot be obtained graphically
  2. Certain facts in arithmetic mean may not be revealed
  3. It may be difficult to obtain without calculation
  4. It can lead to distorted result


A man is able to save N50.00 of his salary in a particular year.  After, every year he saved N20.00 more than the preceding year.  How long does it take him to save N4370?  JAMB

Join Discussion Forum and do your assignment: Find questions at the end of each lesson, Click here to discuss your answers in the forum

For advert placement/partnership, write

Download our free Android Mobile application: Save your data when you use our free app. Click picture to download. No subscription. stoplearn

We are interested in promoting FREE learning. Tell your friends about Click the share button below!