The word statistics comes from the Latin word status meaning a political state, it originally meant information useful to the state, for example, information about the sizes of population of the armed forces. But this word has acquired different meanings.
It is defined as a discipline that includes procedure and techniques used to collect, process and analyze numerical data to make inferences and to reach decisions in the face of uncertainty. Statistics are the numerical quantities calculated from sample observation, a single quantity that has been calculated is called a statistic.
As a subject statistics can be divided into two parts:
Descriptive statistics is that branch of statistics which deals with concepts and methods concerned with summarization and description of the important aspects of numerical data. This area of study consists of the condensation of data, their graphical displays and the computation of a few numerical quantities that provide information about the centre of the data and indicate the spread of the observations.
Inferential statistics deals with procedures for making inferences about the characteristics that describe the larger group of data or the whole, called the population, from the knowledge derived from only a part of the data, called a sample.
CHARACTERISTICS OF STATISTICS
- It deals with the behaviour of aggregates or large groups of data. It has nothing to do with what is happening to a particular individual or object of the aggregate.
- It deals with the variability that obscure underlying patterns. No two objects in the universe are exactly alike. If they were there would have been no statistical problem.
- It deals with the uncertainities as every process of getting observations whether controlled or uncontrolled, involves deficiencies or chance variation.That is why we have to talk in terms of probability.
- It deals with those characteristics or aspects of things which can be described numerically either by counts or by measurements.
- Statistics deals with those aggregates which are subject to a number of random causes e.g. the heights of persons are subject to a number of causes such as race, ancestry, age, diet, habits, climate and so many other factors.
- Laws of statistics are valid on the average or in the long run. There is no guarantee that a certain law will hold in all cases. Statistical inference is therefore made in the face of uncertainty.
- Statistical results may be misleading and incorrect if sufficient care in collecting, processing and interprating the data is not exercised or if the statistical data are handled by a person who is not well versed in the subject matter of statistics.
IMPORTANCE OF STATISTICS
- Statistics assists in summarizing the larger sets of data in a form that is easily understandable.
- Statistics assists in efficient design of laboratory and field experiments as well as surveys.
- Statistics assists in sound and effective planning in any field of inquiry.
- Statistic assists in drawing general conclusions and in making predictions of hoe much of a thing will happen under given conditions.
- Statistical techniques being powerful tools for analyzing numerical data are used in almost every branch of learning. In the biological and physical sciences, Genetics, etc. are the main areas where statistical techniques have been developed and are increasingly used.
- A businessman, an industrialist and a research worker all employ statistical methods in their work. Banks, insurance companies and governments all have their statistics departments.
- A modern administrator whether in public or private sector, leans on statistical data to provide a factual basis for decisions.
- A politician uses statistical advantageously to lend support and credence to his arguments while elucidating the problems he handles.
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