DDepending on the context, whether mathematical or statistical, what is meant by "**mean**" changes. In its simplest mathematical definition regarding data sets, the mean used is the arithmetic mean, also referred to as mathematical expectation, or average. In this form, the mean refers to an intermediate value between a discrete set of numbers, namely, the sum of all values in the data set, divided by the total number of values.

For example, the arithmetic mean between 3, 10 and 8 is calculated as follows: `bar x = (3+10+8)/3 = 21/3 = 7`.

Created with GeoGebra by Vitor Nunes

Try moving the end sides of the chart bars. The values of the `f_i` column (absolute frequencies) are changed and the mean is recalculated.

Statistics provide us with the necessary techniques to be able to extract information from a set of data. These data are often presented "raw" or "incomplete" in that they give us useful information about the problem under study but do not highlight any of its important aspects. Thus, the goal of statistics is to extract information from the data to gain a better understanding of the situations they represent. Some statistical practices include, for example, the planning, aggregation and interpretation of observations. Your goal is always to produce the best possible information from the available data. This information is often vital in making important decisions!