Mean

Overview

When there is many elements in a dataset, it would be useful to have a measure that best represents the dataset. Such a measure would be the central element in within the data data-set. When the data has a normal distribution this central tendency could be best described by the average. In statistics the more formal term for average is mean ().

The mean is the sum of all the data elements (x₁…x_n) divided by the count (n). This can be mathematically represented as follows:

Where,

first element

last element

count

Example 1.
The weight (kg) of children in a small class is as follows: 17.1, 15.4, 13.5, 18.7,19.4. What is the average weight of the children in the class?

Answer.

The cunt (n)

 

The sum of the weights:

 

The mean: