YOUR
INVISIBLE TUTOR: You
are welcome, First of all, lets Introduce what the course
statistics is, throughout this month, we shall be treating the introductory
part of this wonderful course, always check back for next topic.
Meaning
of statistics: The word ‘statistics’ has three different meanings (sense):
Plural sense, singular sense, and plural of the word ‘statistic’ which are
discussed below.
1. Plural
sense: In the plural sense, the word
statistics refer to numerical facts and figures collected in a systematic
manner, with a definite purpose in any field of study. In this sense,
statistics are also an aggregate of facts which are expressed in numerical form
(statistical data). For example, statistics on industrial production,
statistics on population growth, employment rate, interest rate, prices and
wages, exports and imports of a country in different years, etc. It is in this
sense that the word ‘statistics is used by a layman or a newspaper.
2. Singular
Sense: In a singular sense, it refers to
the science of methods used in the collection, analysis, interpretation and
presentation of numerical data. These methods are used to draw conclusion about
population parameter. These are measures of location, variation, probability,
correlation and regression, analysis of variance, and so on. For example: if we
want to have a study about the distribution of weights of student in a certain college,
we will first collect data on their weights, which may be obtained from records
of the college or from the students directly. The large number of weight
figures will confuse the mind. In this situation, we may arrange the weights in
groups, such as 50kg to 60kg, 60kg to 70kg, and so on, and find the number of
students within each group. This step is called a presentation of data. We may
still go further and compute the averages and some other measures which may
give us a complete description of the original data.
3. Plural
of the Word ‘Statistic’: ‘Statistics’ is often used as the plural of ‘statistics’,
which refers to a numerical quantity like mean, median, variance, etc, calculated
from sample value. For example: If we
select 15 students from a class of 80, measure their heights and find the
average height, the average would be statistic.
Statistics,
like many other science, is a developing discipline, it’s not nothing static. It
has gradually developed during the last few centuries; the characteristics of
statistics are;
·
Aggregate of facts
·
Affected by multiplicity
·
Numerically expressed
·
Estimated according to reasonable
standards of accuracy
·
Collected in a systematic manner
·
Collected for a predetermined purpose
·
Placed in relation to each other.
Statistics
both in singular and plural sense has been combined in the following definition,
which is accepted as the modern definition of statistics:
Statistics
are the numerical statement of facts capable of analysis and interpretation and
the science of statistics is the study of the principles and methods applied in
collecting, presenting, analyzing and interpreting numerical data in any field
of enquiry.
In
a more simple way, statistics is concerned with specific methods for collecting,
organizing, summarizing, presenting and analyzing data as well as deriving
valid conclusions and making reasonable decisions on the basis of this
analyzing. Statistics is concerned with the systematic collection of numerical
data and their interpretation; that is, statistics is a set of rules and
procedures for reducing large masses of data to manage proportions. Croxton and
Cowden stated that statistics is the science of collection, presentation,
analysis and interpretation of numerical data from logical analysis. The
definition of statistics by Croxton and Cowden is the most scientific and
realistic. According to it, there are four stages:
·
Collection of Data: This is the
foundation upon which the entire data set. Careful planning is essential before
data collection, there are different methods of collection of data such as
census, sampling, primary, secondary, etc; and the investigator should make use
of correct data method.
·
Presentation of data: The mass data
collected should be presented in a suitable ,concise form of analysis. The collected
data may be presented in a tabular, diagrammatic or graphical form.
·
Analysis of Data: The data presented
should be carefully analyzed for making inference from presented data, such as
measures of tendencies, dispersion, correlation, regression etc.
Interpretation of Data: The final step is
drawing conclusion from the data collected. A valid conclusion must be drawn on
the basis of analysis. A high degree of skill and experience is necessary for
the interpretation.
USES OF STATISTICS
1. To
present a data in a concise and definite form; statistics helps in classifying
and tabulating raw data for processing and further tabulation for end users.
2. To
make it easy to understand complex data: This is done by presenting the data in
form of tables, graphs, diagrams, etc or by condensing the data with the help
of means, dispersion, etc .
3. For
comparison: tables, measures of means and dispersion can help in comparing
different sets of data.
4. In
forming policies: it helps in forming policies, like a production schedule,
based on the relevant sales figures. It is used in forecasting future demands.
5. Enlarging
individual experiences: complex problems can be well understood by statistics,
as the conclusions drawn by an individual are more definite and precise than
the mere statements of facts.
6. In
measuring the magnitude of a phenomenon: statistics has made it possible to
count the population of a country, the industrial growth, the agricultural
growth, the educational level in
numbers.
The Brain Behind this Blog
