CHAPTER 1 : INTRODUCTION
1.1 What
is Statistics
The word 'Statistics'
is derived from the Latin word 'Statis' which means a "political
state." Clearly, statistics is closely linked with the
administrative affairs of a state such as facts and figures regarding
defense force, population, housing, food, financial resources etc.
What is true about a government is also true about industrial administration
units, and even one’s personal life.
The
word statistics has several meanings. In the first place, it is
a plural noun which describes a collection of numerical data
such as employment statistics, accident statistics, population statistics,
birth and death, income and expenditure, of exports and imports
etc. It is in this sense that the word 'statistics' is used by a
layman or a newspaper.
Secondly the word statistics
as a singular noun, is used to describe a branch of applied
mathematics, whose purpose is to provide methods of dealing with
a collections of data and extracting information from them in compact
form by tabulating, summarizing and analyzing the numerical data
or a set of observations.
The various methods
used are termed as statistical methods and the person using
them is known as a statistician. A statistician is concerned with
the analysis and interpretation of the data and drawing valid worthwhile
conclusions from the same.
It is in the second
sense that we are writing this guide on statistics.
Lastly the word statistics
is used in a specialized sense. It describes various numerical items
which are produced by using statistics ( in the second sense ) to
statistics ( in the first sense ). Averages, standard deviation
etc. are all statistics in this specialized third sense.
The word ’statistics’
in the first sense is defined by Professor Secrit as follows:
"By statistics
we mean aggregate of facts affected to a marked extent by multiplicity
of causes, numerically expressed, enumerated or estimated according
to reasonable standard of accuracy, collected in a systematic manner
for a predetermined purpose and placed in relation to each other."
This definition gives
all the characteristics of statistics which are (1) Aggregate
of facts (2) Affected by multiplicity of causes (3) Numerically
expressed (4) Estimated according to reasonable standards of accuracy
(5) Collected in a systematic manner (6) Collected for a predetermined
purpose (7) Placed in relation to each other.
The word 'statistics'
in the second sense is defined by Croxton and Cowden as follows:
"The collection,
presentation, analysis and interpretation of the numerical data."
This definition clearly
points out four stages in a statistical investigation, namely:
1) Collection of
data 2) Presentation of data
3) Analysis of data 4) Interpretation
of data
In addition to this, one more stage
i.e. organization of data is suggested.
