14-02-2013, 12:15 PM
Definition of Statistics:
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Definition of Statistics:
Statistics like many other sciences is a developing discipline. It is not nothing static. It has gradually developed during last few centuries. In different times, it has been defined in different manners. Some definitions of the past look very strange today but those definitions had their place in their own time. Defining a subject has always been difficult task. A good definition of today may be discarded in future.
Characteristics of Statistics:
Some of its important characteristics are given below:
• Statistics are aggregates of facts.
• Statistics are numerically expressed.
• Statistics are affected to a marked extent by multiplicity of causes.
• Statistics are enumerated or estimated according to a reasonable standard of accuracy.
• Statistics are collected for a predetermine purpose.
• Statistics are collected in a systemic manner.
• Statistics must be comparable to each other.
Kinds or Branches of Statistics:
Statistics may be divided into two main branches:
(1) Descriptive Statistics (2) Inferential Statistics
(1) Descriptive Statistics:
In descriptive statistics, it deals with collection of data, its presentation in various forms, such as tables, graphs and diagrams and findings averages and other measures which would describe the data.
For Example: Industrial statistics, population statistics, trade statistics etc… Such as businessman make to use descriptive statistics in presenting their annual reports, final accounts, bank statements.
(2) Inferential Statistics:
In inferential statistics, it deals with techniques used for analysis of data, making the estimates and drawing conclusions from limited information taken on sample basis and testing the reliability of the estimates.
For Example: Suppose we want to have an idea about the percentage of illiterates in our country. We take a sample from the population and find the proportion of illiterates in the sample. This sample proportion with the help of probability enables us to make some inferences about the population proportion. This study belongs to inferential statistics.
Difference between Primary and Secondary Data:
The difference between primary and secondary data is only a change of hand. The primary data are the first hand data information which is directly collected form one source. They are most original data in character and have not undergone any sort of statistical treatment while the secondary data are obtained from some other sources or agencies. They are not pure in character and have undergone some treatment at least once.
For Example: Suppose we interested to find the average age of MS students. We collect the age’s data by two methods; either by directly collecting from each student himself personally or getting their ages from the university record. The data collected by the direct personal investigation is called primary data and the data obtained from the university record is called secondary data.