In our days, statistics have become an effective method to accurately describe the values of economic, political, social, psychological, biological and physical data, and it serves as a tool to relate and analyze such data. The job of the statistical expert is no longer only to collect and tabulate the data, but above all the process of interpreting that information.
The development of probability theory has increased the scope of the applications of statistics. Many data sets can be approximated, with great accuracy, using certain probability distributions; the results of these can be used to analyze statistical data.
Probability is useful for checking the reliability of statistical inferences and for predicting the type and amount of data required in a given statistical study.