what is statistic and characteristic of statistic?

Meaning of statistics:

The word statistics is used to give the following three meanings.

Firstly it is used in plural sense which refers to the collection of numerical data in aggregate form relating to any field of stud e.g. statistics of births, statistics of prices, statistics of road accidents etc.

Secondly it is used in singular sense which refers to the methods and procedures used in the collection, analysis, interpretation of data and presently the data in various forms such as tables, graphs, charts, diagrams and finding averages and other measure which would describable the data.

Thirdly it is used in a technical sense as plural of ht word “STATISTIC”. By statistic we mean a quantity such as mean, median, s.d etc computed from sample data e.g. if we select a sample of 20 students from a class containing 100 students and find their average height, then this average is called statistic.

Characteristics of statistics:

The fundamental characteristics of statistics are described below.

1.                 Statistics are aggregate of facts:

Statistics are aggregate of facts. A single figure cannot called statistics. Because can be drawn about such figures e.g. if we say that income of a person is RS 500, this figure is meaningless, because we cannot draw any conclusion about this figure i.e. whether the income of a person has increased or decrease. Thus the science of statistics is the science of aggregate and not of individuals.

2.                 Statistics are affected by multiplicity of causes:

Statistics (i.e. figure) obtained about a particular phenomena are due to a number of causes e.g. production of wheat depends on seeds, fertilizer, irrigation, rainfall etc. it is not possible to study the influence of these factors separately, because these factors jointly determine the yield.  

3.                 Statistics are numerically expressed:

Statistics are numerical statement of facts. Qualitative expression such as honestly, good, bad etc. do not form statistics e.g. consider the following statement “QUAID AZAM was a great leader”. This is not a statistics statement. If on the other hand, we say that per capita income in Pakistan in 1960 was RS 840 and RS 1400 in 1990. This is of course a statistics statement as per capita incomes is expressed numerically and is comparable.           

4.                 Statistics are collected in a systematic manner:

When statistics are collected in a systematic manner, then they may give accurate result. If they are collected in a haphazard manner, then the very purpose of collecting statistics will be damaged such statistics always leads to misleading conclusions. Thus there must be trained investigators and proper organizations for the collection of statistics.  

5.                 Statistics are placed in relation to each other:

Statistics are collected mainly for the purpose of comparison. Data collected must be comparable and homogenous e.g. if we compare the heights of persons with their income, it is not statistics, on the other hand if we compare the ages of husbands with the ages of their wives. Then it is called statistics.

6.                 Statistics are collected for a per-determined purpose:

The purpose for which statistics are to be collected is always determined in advance. It enables the investigator to distinguish between wanted and unwanted data. If the purpose is not determined in advance, then investigator may collect the irrelevant data.