Statistics Notes

Statistics Introduction:

A body of procedure and techniques used to collect, process and analyze (investigate) numerical data to make inferences and to reach decisions in the face of uncertainty.

Simply we can say gathering data + processing of data = result (our decision)

Little History:

The word statistics which comes from Latin word status, meaning a polital state, originally meant information useful to state.
Al-kindi starts the concepts of statistics developing the first code breaking algorithm based on frequency analysis. He writes a book “MAN SUSCROPT ON DECIPHERINS CRYPTOGRAPHIC MESSAGE”, he born in801 and leaves the world 873. His nationality is Iraqi.
There is another man who developed the concepts of probability now known as byes theorem. He was a English man, birth date is 1702 and died in 1761.

Uses of statistical data:

• Statistical data explain things what’s going on.
• Statistical data justify a claim.
• To provide general comparison.
• Statistical data helps to estimate unknown quantities.
• Its helps to make relationship between different factors.

Statistics deals with the behavior of aggregates or leakage group of data. It deals with aggregates of observation of same kind rather than isolated figures. It deals with variability that obscures underlying patterns.
Some time in statistics data may be wrong during collecting process thus we can say statistics deals with uncertainties as every process of getting observation.
Statistics can be divided into subjects

• Descriptive statistics
• Inferential statistics

Descriptive statistics:

It is the branch of statistics which deals with concepts and the methods concerned with description of the important aspects of numerical data.

Inferential statistics:

It is the branch of statistics which deals with methods (procedure) for making inferences about the characteristics that describe the large group of data called population, from the knowledge derived from only part of the data, known as sample.