Introduction to
Statistics
Santosh Bhandari
Why study statistics?
1. Data are everywhere
2. Statistical techniques are used to make many
decisions that affect our lives
3. No matter what your career, you will make
professional decisions that involve data. An
understanding of statistical methods will help you
make these decisions efectively. etc
Meaning
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The term “Statistics” from latin word “status”
Italian words “statista” means Statement
German worlds “statistik” means political State
Statistics is concerned with scientific methods for
collecting,
organizing,
Summarizing,
presenting and analyzing data
as well as deriving valid conclusions and making reasonable decisions on the basis of this analysis.
Francis Galton, Bernoulli, Karl Person, Ronald Fisher etc are main contribution to develop the
statistics'.
Definition of Statistics in singular
sense
 Statistics as the science of counting or science of average (A.L.
Bowley)
 Statistics as the science of estimates and probabilities (Boddington)
 Statistics is the science which deals with the method of collection,
classifying, presenting, comparing and interpreting numerical data
collected to throw some light in any sphere of enquiry (Selligman).
 Statistics may be regarded as a body of methods for making wise
decision in the face of uncertainty(Wallis and Roberts ).
 Statistics may be defined as the science of collections,
presentation, analysis and interpretation of the data(Croxton &
Cowden).
Definition of Statistics in plural
sense
 Statistics are the classified facts representing the
conditions of the people in given state(Webster).
 Statistics are numerical statement of facts in any
department of enquiry placed in relation to each
others(Bowley).
 Statistics may be defined as the aggregate of fact, affected
to a marked extent, by multiplicity of causes, numerically
expressed, enumerated or estimated according to a
reasonable standard of accuracy, collected a systematic
manner for predetermined purpose and placed in relation
to each others(Prof. Horace Secrist).
Use & scope of Statistics
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Planning
Economics
Business & Management
Industry
Physical sciences
Biological sciences
Social sciences
Information Technology
Agriculture
Insurance
Education & Psychology
Functions of Statistics
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Simplifies complexity
Facilities of comparison
To help Formulation of policies
To help Classification of data
Help in formulating and testing hypothesis
To help predicting future trends
Test the law of others science
Enlarge individual experience
Thus main function of statistics are Condensation , Comparison , Forecasting,
Estimation .
Limitation of Statistics
• Does not deals with individuals
• Statistics does not study the
qualitative phenomena.
• Statistics laws are not exact
• Statistics is only means
• Statistics can be misused
Types of Statistics
Theoretical
or
Mathematical
Descriptive
Applied
Inferential
Descriptive Statistics
• It deals with methods which help in estimating the
characteristics of a population or making decisions
concerning a population on the basis of the sample
results. Sample and population are the two relative
terms. A Population is treated as universe and a
sample is fraction or segment of the universe.
• Summary and favor of distribution.
• Tabular, graphical or numerical are termed are used like wise
Average, rates, ratios etc.
• Measure of central tendency, skewness, kurtosis etc.
Inferential Statistics
It means to describe the data and consists of the methods and
techniques used in the collection, organization, presentation and
analysis of data in order to describe the various features and
characteristics of such data. These can either be graphical or
computational. In this, nothing can be inferred from the data nor can
decision be made or conclusion drawn.
Applied Statistics
• This consists of massive application of
theoretical or mathematical.
• The statistical tools and methods are used
in order to solve many more practical
problems in diversified area.
• Applied statistics has played very
important role in decision making
problem as well.
Types & Sources of Data
• All statistical analysis begins by identifying the source
of the data. Among the important sources of data
are published sources, experiments, and surveys.
• Statistical data are mainly depending the sources of
two types
A. Primary Data
B. Secondary Data
Primary Data
• Fresh and original data, which are collected and recorded
by the investigator or researchers for the specific purpose.
• Following method are using the collect the primary data;
a) Direct Personal Interview
b) Indirect oral interview
c) Information through correspondents
d) Mailed questionnaire
e) Schedules sent through enumerators
Secondary data
• Data are already collected
• The sources of data are
1. Publish Sources(Reports and official publications,
Semi-official publication, un-official or private
publicaion)
2. Unpublished Sources
Precautions in the use of secondary
Data
• Suitability
• Reliability
• Adequacy
Thank you all