Introduction to Statistics
Origin – It is either derived from the word Latin
word Status or Italian word Stato or German word
Statistick. In all the three languages it means ‘an
organized political state’.
Meaning of Statistics
Statistics has multiple meanings depending upon
the person using it. For a common man it is just a
data or a fact or a measurement. Some may regard
it as study of figures, for some it is analysis of
figures for forecasting or drawing inferences.
Diagrammatic or graphic representation of facts is
also considered as statistics.
Unit I Introduction to Statistics
Processing, analysis and application of
quantitative facts is also regarded as
Statistics. In general it can be of following
forms –
As a product – Data
As a process – Statistical methods
As an application – Methods and
theories
used to handle
numerical data for
inferential decision
purposes.
Unit I Introduction to Statistics
Definition of Statistics –
According to Horace Secrist, “By statistics we mean
aggregate of facts affected to a marked extent by
multiplicity of causes, numerically expressed,
enumerated or estimated according to reasonable
standards of accuracy, collected in a systematic manner
for a pre-determined purpose and placed in relation to
each other”.
Unit I Introduction to Statistics
The definition mentions the characteristics which data
should possess. As per the definition it should have
following features –
1. Statistics are aggregates of facts – single or
unrelated figures are not statistics, because they do
not throw light on any problem. Statistical data are
concrete numbers which represent objects. Numbers
like 20, 25, 18, 23 etc. cannot be called statistics but
if they are placed in a series indicating ages of 20 and
25 years of the husbands the respective ages of wives
are 18 and 23 years, then these figures are termed as
statistics.
Unit I Introduction to Statistics
2. Affected to a marked extent by multiplicity of
causes – Statistics refer to the measurement of
phenomena in a complex universe. They are related to
various factors surrounding them. Hence to say that
statistics are affected by a single factor is not correct.
3. Numerically expressed, enumerated or estimated –
The facts which are to be called as statistical data are
expressed numerically as it adds a value to it.
Unit I Introduction to Statistics
4. According to the reasonable standards of accuracy –
There has to be certain rules while collecting data
associated. This is necessary to maintain homogeneity
of data.
5. Collected in a systematic manner for a pre-
determined purpose – Data is collected as per a set of
rules decided prior to the collection to avoid any kind
of redundancy as well as inaccuracy.
Unit I Introduction to Statistics
6. Placed in relation to each other – Data is usually
collected for comparing it with other type of similar
data so that certain conclusion can be drawn.
Unit I Introduction to Statistics
Other definitions of Statistics –
A. L. Bowley – He gave following three definitions of
statistics –
1. Statistics is the science of counting.
2. Statistics may rightly be called as science of
Averages.
3. Statistics is the science of the measurement of
social organism regarded as a whole in all its
manifestations.
Unit I Introduction to Statistics
Modern Definitions of Statistics –
1. W. I. King – The science of statistics is the method
of judging collective, natural or social phenomena
from the results obtained by the analysis of an
enumeration or collection of estimates.
2. P. H. Karmel – The subject statistics is concerned
with the collection, presentation, description and
analysis of data which are measurable in numerical
form.
Unit I Introduction to Statistics
3. Seligman – Statistics is the science which deals with
the methods of collecting, presenting, comparing and
interpreting numerical data collected to throw some
light on any sphere of inquiry.
4. Wallis and Roberts – Statistics is a body of methods
making wise decisions in the face of uncertainty.
Unit I Introduction to Statistics
5. Fisher – Statistics may be regarded as
a. The study of population,
b. The study of variation,
c. The study of methods of reduction of data.
In general, “Statistics is a science and an art which
deals with collection, classification, tabulation,
presentation, establishment of relationship,
interpretation and forecasting of data in connection
with social, economic, natural and other problems so
that the predetermined aims may be achieved”.
Unit I Introduction to Statistics
As per the above definition there are five stages in a
statistical investigation –
1. Collection – Collecting data is the first step in a
statistical investigation. Data must be collected with
maximum care and accuracy as it forms the foundation
of the statistical analysis. In case faulty data is
collected wrong conclusions will be drawn. The first
hand collection of data is very difficult and important
task faced by the statistician. An investigator must
view data collected earlier so that repetition and
waste of time and resource can be avoided.
Unit I Introduction to Statistics
2. Organization – Data collected from published
sources are generally in organized form. However, a
large mass of figures that are collected from a survey
needs to be organized. The first step is to edit the
data. It must be edited carefully so that omissions,
inconsistencies, irrelevant answers and wrong
computations can be adjusted / corrected. After
editing data it must be classified according to some
common characteristics. Tabulation is the last step in
the organization.
Unit I Introduction to Statistics
3. Presentation – After the data is collected and
organized it is ready for presentation. Data presented
in an orderly manner facilitate statistical analysis.
There are two different modes in which the collected
data can be presented –
1. Diagrams
2. Graphs
4. Analysis – After collection, organization and
presentation the next step is analysis. The purpose of
analyzing data is to dig out information useful for
decision making.
Unit I Introduction to Statistics
5. Interpretation – The final stage in statistical
investigation is interpretation, i.e. drawing inferences
/ conclusions form the data collected and analyzed.
Interpretation is a difficult task and needs a high level
of expertise and experience.
Functions of Statistics –
1. It represents facts in a definite form.
2. It simplifies mass of figures.
3. It facilitates comparison.
4. It helps in formulating and testing hypothesis.
5. It helps in prediction.
6. It helps in the formulation of suitable policies.
Unit I Introduction to Statistics
Application of Statistics –
Statistics and the State – Since ancient times the ruling
kings and chiefs have relied prominently on statistics
in framing suitable military and fiscal policies. Most of
the statistics related to crimes, military strength,
population, taxes etc.
Statistics and Mathematics –
Statistics is a branch of science based on mathematics.
It attempts to formulate definite rules of procedure
applicable in handling groups of data of many different
varieties.
Unit I Introduction to Statistics
Statistics and Economics – Economic policies are often
designed on the basis of statistics. Various economic
laws and theories were propounded after statistical
tests. Statistical methods help in deriving economic
laws and also in providing the validity of existing
economic laws. It helps in developing the empirical
laws side of economics.
Statistics and Physical Sciences – Various sciences like
biology, physics, chemistry, Astrology, Medicines etc.
use statistical methods. In these sciences statistical
data are collected from the results of experiments.
Unit I Introduction to Statistics
Statistics and Social Sciences – Statistics is widely used
in social sciences. Political science, geography, history,
psychology etc. use statistical methods in
investigations and research in their respective fields.
I.Q computation in psychology is done using statistical
methods.
Statistics and Industry and Commerce – Statistical
methods and procedures are employed by business
managers. Data recorded on commercial transactions
gives an insight regarding buying/selling pattern and
helps in forecasting.
Unit I Introduction to Statistics
Functions of Statistics –
1. To simplify complex data.
2. To provide comparative studies.
3. To study relationships between different facts.
4. To enlarge individual knowledge and experience.
5. To formulate policies in different fields.
6. To measure effects.
7. To test a hypothesis.
8. To provide numerical measurement.
9. To forecast.
Unit I Introduction to Statistics
Limitations of Statistics –
1. Statistics only studies the quantitative aspects of a
problem and does not study the quantitative aspects.
2. Statistics deals with averages.
3. Statistics does not study individuals.
4. Statistical results are only approximately correct.
5. Statistical results are not always beyond doubt.
6. Statistics is only a mean.
Unit I Introduction to Statistics

Inroduction to statistics

  • 2.
    Introduction to Statistics Origin– It is either derived from the word Latin word Status or Italian word Stato or German word Statistick. In all the three languages it means ‘an organized political state’. Meaning of Statistics Statistics has multiple meanings depending upon the person using it. For a common man it is just a data or a fact or a measurement. Some may regard it as study of figures, for some it is analysis of figures for forecasting or drawing inferences. Diagrammatic or graphic representation of facts is also considered as statistics. Unit I Introduction to Statistics
  • 3.
    Processing, analysis andapplication of quantitative facts is also regarded as Statistics. In general it can be of following forms – As a product – Data As a process – Statistical methods As an application – Methods and theories used to handle numerical data for inferential decision purposes. Unit I Introduction to Statistics
  • 4.
    Definition of Statistics– According to Horace Secrist, “By statistics we mean aggregate of facts affected to a marked extent by multiplicity of causes, numerically expressed, enumerated or estimated according to reasonable standards of accuracy, collected in a systematic manner for a pre-determined purpose and placed in relation to each other”. Unit I Introduction to Statistics
  • 5.
    The definition mentionsthe characteristics which data should possess. As per the definition it should have following features – 1. Statistics are aggregates of facts – single or unrelated figures are not statistics, because they do not throw light on any problem. Statistical data are concrete numbers which represent objects. Numbers like 20, 25, 18, 23 etc. cannot be called statistics but if they are placed in a series indicating ages of 20 and 25 years of the husbands the respective ages of wives are 18 and 23 years, then these figures are termed as statistics. Unit I Introduction to Statistics
  • 6.
    2. Affected toa marked extent by multiplicity of causes – Statistics refer to the measurement of phenomena in a complex universe. They are related to various factors surrounding them. Hence to say that statistics are affected by a single factor is not correct. 3. Numerically expressed, enumerated or estimated – The facts which are to be called as statistical data are expressed numerically as it adds a value to it. Unit I Introduction to Statistics
  • 7.
    4. According tothe reasonable standards of accuracy – There has to be certain rules while collecting data associated. This is necessary to maintain homogeneity of data. 5. Collected in a systematic manner for a pre- determined purpose – Data is collected as per a set of rules decided prior to the collection to avoid any kind of redundancy as well as inaccuracy. Unit I Introduction to Statistics
  • 8.
    6. Placed inrelation to each other – Data is usually collected for comparing it with other type of similar data so that certain conclusion can be drawn. Unit I Introduction to Statistics
  • 9.
    Other definitions ofStatistics – A. L. Bowley – He gave following three definitions of statistics – 1. Statistics is the science of counting. 2. Statistics may rightly be called as science of Averages. 3. Statistics is the science of the measurement of social organism regarded as a whole in all its manifestations. Unit I Introduction to Statistics
  • 10.
    Modern Definitions ofStatistics – 1. W. I. King – The science of statistics is the method of judging collective, natural or social phenomena from the results obtained by the analysis of an enumeration or collection of estimates. 2. P. H. Karmel – The subject statistics is concerned with the collection, presentation, description and analysis of data which are measurable in numerical form. Unit I Introduction to Statistics
  • 11.
    3. Seligman –Statistics is the science which deals with the methods of collecting, presenting, comparing and interpreting numerical data collected to throw some light on any sphere of inquiry. 4. Wallis and Roberts – Statistics is a body of methods making wise decisions in the face of uncertainty. Unit I Introduction to Statistics
  • 12.
    5. Fisher –Statistics may be regarded as a. The study of population, b. The study of variation, c. The study of methods of reduction of data. In general, “Statistics is a science and an art which deals with collection, classification, tabulation, presentation, establishment of relationship, interpretation and forecasting of data in connection with social, economic, natural and other problems so that the predetermined aims may be achieved”. Unit I Introduction to Statistics
  • 13.
    As per theabove definition there are five stages in a statistical investigation – 1. Collection – Collecting data is the first step in a statistical investigation. Data must be collected with maximum care and accuracy as it forms the foundation of the statistical analysis. In case faulty data is collected wrong conclusions will be drawn. The first hand collection of data is very difficult and important task faced by the statistician. An investigator must view data collected earlier so that repetition and waste of time and resource can be avoided. Unit I Introduction to Statistics
  • 14.
    2. Organization –Data collected from published sources are generally in organized form. However, a large mass of figures that are collected from a survey needs to be organized. The first step is to edit the data. It must be edited carefully so that omissions, inconsistencies, irrelevant answers and wrong computations can be adjusted / corrected. After editing data it must be classified according to some common characteristics. Tabulation is the last step in the organization. Unit I Introduction to Statistics
  • 15.
    3. Presentation –After the data is collected and organized it is ready for presentation. Data presented in an orderly manner facilitate statistical analysis. There are two different modes in which the collected data can be presented – 1. Diagrams 2. Graphs 4. Analysis – After collection, organization and presentation the next step is analysis. The purpose of analyzing data is to dig out information useful for decision making. Unit I Introduction to Statistics
  • 16.
    5. Interpretation –The final stage in statistical investigation is interpretation, i.e. drawing inferences / conclusions form the data collected and analyzed. Interpretation is a difficult task and needs a high level of expertise and experience. Functions of Statistics – 1. It represents facts in a definite form. 2. It simplifies mass of figures. 3. It facilitates comparison. 4. It helps in formulating and testing hypothesis. 5. It helps in prediction. 6. It helps in the formulation of suitable policies. Unit I Introduction to Statistics
  • 17.
    Application of Statistics– Statistics and the State – Since ancient times the ruling kings and chiefs have relied prominently on statistics in framing suitable military and fiscal policies. Most of the statistics related to crimes, military strength, population, taxes etc. Statistics and Mathematics – Statistics is a branch of science based on mathematics. It attempts to formulate definite rules of procedure applicable in handling groups of data of many different varieties. Unit I Introduction to Statistics
  • 18.
    Statistics and Economics– Economic policies are often designed on the basis of statistics. Various economic laws and theories were propounded after statistical tests. Statistical methods help in deriving economic laws and also in providing the validity of existing economic laws. It helps in developing the empirical laws side of economics. Statistics and Physical Sciences – Various sciences like biology, physics, chemistry, Astrology, Medicines etc. use statistical methods. In these sciences statistical data are collected from the results of experiments. Unit I Introduction to Statistics
  • 19.
    Statistics and SocialSciences – Statistics is widely used in social sciences. Political science, geography, history, psychology etc. use statistical methods in investigations and research in their respective fields. I.Q computation in psychology is done using statistical methods. Statistics and Industry and Commerce – Statistical methods and procedures are employed by business managers. Data recorded on commercial transactions gives an insight regarding buying/selling pattern and helps in forecasting. Unit I Introduction to Statistics
  • 20.
    Functions of Statistics– 1. To simplify complex data. 2. To provide comparative studies. 3. To study relationships between different facts. 4. To enlarge individual knowledge and experience. 5. To formulate policies in different fields. 6. To measure effects. 7. To test a hypothesis. 8. To provide numerical measurement. 9. To forecast. Unit I Introduction to Statistics
  • 21.
    Limitations of Statistics– 1. Statistics only studies the quantitative aspects of a problem and does not study the quantitative aspects. 2. Statistics deals with averages. 3. Statistics does not study individuals. 4. Statistical results are only approximately correct. 5. Statistical results are not always beyond doubt. 6. Statistics is only a mean. Unit I Introduction to Statistics