Statistics plays an important role in all our lives. For example, citizens are counted in the population census taken by the government for various reasons. Business people conduct surveys to find out what products are most frequently wanted by consumers; and so on.

Meaning of Statistics

There are many definitions of the term statistics given by different scholars. However, for the purpose of this unit, we will confine ourselves to the following:

Definition

Statistics is the science of collecting, organizing, presenting, analyzing and interpreting data (quantitative information) in order to draw conclusions.

Basically, statistics is a procedural process performing five logical steps on numerical data. These are:

1. Collection of data: This is the process of obtaining measurements or counts. For example, measuring the heights of students in your class, or counting the number of persons admitted to a certain hospital are examples of data collection.
2. Organization of data: The second step of statistics refers to the organization of data. Collected data has to be organized in a suitable form to understand the information gathered. The collected data must be edited, classified and tabulated.
3. Presentation of data: The main purpose of data presentation is to facilitate statistical analysis. This can be done by illustrating the data using graphs and diagrams like bar graph, histograms, pie-charts, pictograms, frequency polygons, etc.
4. Analysis of data: In order to meet the desired purpose of investigation, data has to be analyzed. The purpose of analyzing data is to get information useful for decision making.
5. Interpretation of data: Based on analyzed data, conclusions have to be drawn. This step usually involves decision making about a large collection of objects (the population) based on information gathered from a small collection of similar objects (the sample).