DEFINITION OF STATISTICS
Statistics is a scientific activity which
deals with the theories and methods of
collection, analysis and interpretation of
APPLICATION OR USES OF
1- It deals in presenting large quantity of data in a simple
and classified form.
2- It helps in finding the relationship between the
3- It proves useful in number of fields like railways, banks,
4- It gives the method of comparison of data and judges
them in a right manner.
5- It helps to provide good material for the businessmen
as well as the administrator.
CHARACTERISTIC OF STATISTICS
1- Statistics are the aggregate of facts.
2- It can be numerically expressed.
3- Statistics must be related to some field of inquiry.
4- Statistics are collected for predetermined
5- Statistics are affected by multiplicity of causes
and not by single cause.
6- It should be capable of being placed in relation to
LIMITATIONS OF STATISTICS
1- It does not deal with individual items.
2- It does not depict entire story of phenomenon.
3- It is liable to be misused.
4-Results are true only on average.
5-Too many methods to study problems.
6- Data can not be expressed in qualitative terms.
7- Statistical results are not always beyond doubt.
SAMPLE AND POPULATION
Population in statistics means the whole of
the information which comes under the preview of
statistical investigation. It is the totality of all the
observations of a statistical enquiry.
The number of units or members consisting a
population is known as size of population.
There are two types of population:
1- Finite Population
2- Infinite Population
A part of the population selected for the study is
called a sample. Samples are usually a relatively small
number of observations taken from a relatively large
population or universe.
For eg. A house wife tests a small quantity of rice to
see whether it has been cooked or not. This small
quantity of rice is a sample
COLLECTION OF STATISTICAL
Definition of Statistical Data:
A sequence of observation made on a set of
objects included in the sample drawn from the
population is known as statistical data.
There are two types of data:
1-Ungrouped data: Data which have been arranged
in a systematic order are called ungrouped data or
2-Grouped data: Data presented in the form of
frequency distribution is called grouped data.
COLLECTION OF DATA
The first step in any investigation is collection of data.
There are two types for collection of data:
1- Primary Data: The primary data are the first hand
information collected, compiled and published by
organization for some purpose. They are most original
data in character and have not undergone any sort of
2- Secondary Data: The secondary data are second hand
information which are already collected by someone for
some purpose and are available for the present study.
The secondary data are not pure in character and have
undergone some treatment at least once.
The characteristics which can be measure are known
The quantity which can be numerically expressed
in terms of units and also they can be measured by
For eg. Height, weight, marks etc.
Discrete Variables: Discrete variables are those
variables which take only certain value and none in
between. In case of discrete variables the quantity
are measured in whole in tabular values and they
can not take any fractional value.
For eg. height of students,weight, marks, blood
Continuous variables are those variables
which have no gaps in between.
In other words those quantities which can
take any value with in a specific range is known
as continuous variables.
For eg: Marks of students are divided into a
class interval of 40-50 marks and corresponding
to these marks 5 students lie within the range but
it does not have a specific value or fixed value.