Question

Why we use averages and dispersions?

Answer 1

The term average is used frequently in everyday life to express an amount that is typical for a group of people or things. For example, you may read in a newspaper that on average people watch 3 hours of television per day. ... Averages are useful because they: summarise a large amount of data into a single value; 

While measures of central tendency are used to estimate "normal" values of a dataset, measures of dispersion are important for describing the spread of the data, or its variation around a central value. Two distinct samples may have the same mean or median, but completely different levels of variability, or vice versa.

Answer 2

Averages are used to compare different countries, state or regions.The average also measures the center of the data. Dispersion the word dispersion has a technical meaning in statistics.