Class 11 Notes of Economics HSEB
Definition of Statistics:
The
word ‘Statistics’ has been defined in two senses i.e. singular sense and plural
sense. When the word statistics is used in singular sense, it means various
methods and techniques adopted for the collection, presentation, analysis and
interpretation of data. On the other hand, when the word statistics is used in
plural sense, it refers to data themselves or numerical facts collected
systematically. For eg: Statistics of total population, national income,
export, import, etc.
Definition of statistics in singular sense:
Definition of statistics in singular sense:
According to Croxton &
Cowden, “Statistics may be defined as the
science of collection, presentation, analysis and interpretation of numerical
data.”
This
definition is simple and comprehensive. It clearly indicates the following four
aspects of statistics:
Connection of data:
This
is the first steps of statistical enquiry.
Representation of data:
After
the data has been collected, they are presented in a systematic way. This is
the second step for statistical investigation.
Analysis of data:
After
the data has been presented, the next step is to analyze them.
Intrepretation of data:
The
last step of statistical enquiry is the interpretation of data. In this step,
the researcher has to draw the conclusion from the data which has been analyzed.
Definition of Statistics in plural sense:
According to A.L. Bowley, “Statistics are numerical statement of facts in any department of enquiry, placed in relation to each other.”
This
definition point out the three aspects of statistics:
- Statistics are numerical statement of facts.
- Statistics are concerned with any enquiry.
- Statistics are placed in relation to each other for the purpose of comparison.
Functions of Statistics:
The major functions are as follows:
Statistics simplifies complexity:
Statistics
helps to simplify the raw and complex information by means of organization,
presentation and analysis of data. Huge facts and figures are difficult to
remember. The complex mass of figure can be made simple and understandable with
the help of statistical methods.
Statistics presents facts in definite form:
One
of the important function of statistics is to is to present the general
statements in a definite form. The conclusion stated numerically is definite and
more conviencing than the conclusion sated qualitatively.
Statistics facilitates comparison:
This
is another function of statistics. Unless the figures are compared with other
figures of the same kind, they are meaningless. Statistical techniques like classification,
tabulation, average, ratio etc. can be used for comparison between two or more
group of data.
Statistics helps to formulate policies:
Statistical
data and tools are necessary for formulating suitable policies. Government
policies are formulated on the basis of available data of the country.
Statistics helps in forecasting:
Various
statistical tools and techniques are used to forecast for the future. For Eg:
Regression analysis can be used in forecasting market demand.
Statistics helps in formulating and testing hypothesis:
Statistics
is helpful in formulating and testing the hypothesis for the development of new
theories.
Importance of statistics:
In
ancient time, the importance of statistics was limited. But now, its importance
has been extended in multiple fields of human life. It is important in various
sectors of the economy. The major importance of statistics are as follows:
Importance of statistics to state:
Statistics
is very important to the state. Now – a – days, a state collects statistical
data to solve most of the problems. On the basis of such statistical the state
makes appropriate plan for development.
Importance of Statistics to planning:
In
order to achieve the determined goals, planning is essential for the government
of a country. But without proper statistics, we cannot make any planning. Thus,
statistics plays an important role in planning.
Importance of Statistics to economics:
Many
economists have been using statistical tools and techniques to develop the area
of economics. Therefore, statistics is very essential to develop & prove
the principles & laws of economics.
Importance of Statistics to industrialists and business:
Statistics
is very important for industrialist & businessman. Nowadays, the business
sectors are expanding and become very competitive. Therefore, if they do not
take care of the things like demand, price and market of the commodity they
cannot fully successful.
Importance of Statistics to Mathematics:
Statistics
is the branch of applied mathematics, which is related with data. Modern
theories of statistics have their foundation on mathematical theories.
Similarly, mathematics is also dependent on statistics regarding the
formulation of various mathematical models. Therefore, statistics is important
in mathematics as well.
Limitations of Statistics:
There
are some limitations of statistics which are as follows:
Statistics doesn’t deal with an individual:
Statistics
is always related with groups. It deals with aggregate of facts. Therefore, it
doesn’t deal with an individual.
Statistics doesn’t study qualitative phenomenon:
In
statistics, we study the numerical statements or facts. But it doesnot study
the qualitative characteristics like beauty, honesty, love, etc.
Statistics laws are not exact:
100
% accuracy is rare in statistical work because statistical laws are true only
on the average.
Statistics is only a means:
Statistics
acts as a facilitator subject to other disciplines. It helps to analyze data
and draw conclusions from the findings. Therefore, it is only a means.
Statistics is liable to be misuse:
The
greatest limitation of statistics is that it must be used by experts only. If
statistics are used by those persons who are not expert in this field, then the
conclusion drawn may be wrong.
Statistical data should be of similar nature:
To
draw the correct conclusion the data should be similar in nature. If there are
not of similar types and are of different natures collected by different
techniques then the conclusion drawn from the data could be misleading.
Collection and organization of data:
Types of data:
Primary data:
The
data which is originally collected by an investigator or an agent for the first
time for the purpose of statistical enquiry is called primary data. This data
are original in character. This data are also called first hand data because
such data used for the first time by the investigator. For Eg: If an
investigator wants to study about the educational status of Dharan and if he or
his agent collects the necessary information then, the data is primary.
Secondary data:
The
data which were already collected and used by someone else but are also useful
for other investigators are called secondary data. This types of data are not
original in character for the user. This data are also called second hand data.
For Eg: If an investigator wants to investigate about the educational status of
Dharan and if he uses necessary information from Dharan municipality record, it
is secondary data for the investigator.
Methods of collecting Primary data:
There are various methods of
collecting Primary data which are as follows:
Direct personal interview:
In
this method, the investigator collects the data personally from the source
concerned. In other words, the investigator goes up to the respondents
personally and asks the necessary questions and obtain the required
information.
Indirect oral interview:
In
this method, the investigator obtains the necessary information by contacting
the other persons who are familiar with the problem under study. Such person is
called witness. This method is applied when the informants hesitate to give
information directly.
Information through correspondents:
In
this method, the investigator appoints local agents in different parts of the
field of enquiry. These agents collects the necessary information from their
respective fields and send them to the central office. This method is widely
used by newspapers, radio, TV, to obtain the information.
Mailed questionnaire method:
In this method, first of all, questionnaires are send to individual respondents by post. The respondents are requested to answer all the questions and return the questionnaires by post within a certain period of time.
Schedule sent through enumerators:
In
this method, the questionnaire are sent through the enumerators. The
enumerators go to the respondents personally and ask them the questions and
obtain the necessary information. This method is appropriate if the field of
enquiry is very large.
Source of Secondary data:
There
are various sources of secondary data which are as follows:
- Governments official publication like plan documents, economic survey, budget speech, etc.
- Reports given by various committees and commissions appointed by the government.
- The publications of commercial and trade organization.
- Official publication of Nepal Rastra Bank.
- Official publications of International Agencies like World Bank, IMF, UN, UNDP, WHO, etc.
- Population census, Agriculture census, conducted by CBS (Central Bureau of Statistics).
- Publications of universities and research institution.
- Publication of individual research workers.
- Reports of private organizations.
- Research works conducted by students.
Reliability of Secondary data:
Before
using the secondary data, we should check whether the data are reliable or not.
While testing the reliability the following things should be taken into
consideration.
- Who collected the data and what were the objectives of collecting data?
- Was the investigator experience, honest, capable and unbiased or not?
- Whether the appropriate techniques of collecting data were applied or not.
- What degree of accuracy was maintained in the degree?
- In which time period were the data collected?
Precaution in the uses of secondary data:
Secondary
data are those which are collected by someone else and used by others.
Therefore, while using secondary data the following precautions should be
taken:
- The data should be reliable.
- The data should be suitable.
- The data should be adequate.
Techniques of data collection:
There
are two techniques of data collection. They are:
- Census method:
- Sample method:
Census method:
In
this method, the informations is obtained from each and every units of
population, under study. In other words, if the information is collected from
the possible units in the universe it is called census method. The census
method is also called complete enumeration method. In Nepal, population census is conducted by
applying census in Nepal
every 10 years. For example: If we want to study about the smoking habit of
adults of a locality then, in census method, information are obtained from each
and every adults of that locality.
Merits of census method:
The
following are the merits of census method:
- It gives complete information about the population.
- It gives more accurate, reliable and representative results.
- The data will be adequate because no item is left in this method.
- If the study area is small then this method is very useful.
Demerits of Census method:
The
following are the demerits of census method.
- This method is more expensive and time consuming.
- This method is not applicable if the population is infinite.
- This method is not suitable in some special conditions. For Eg: This method cannot be applied if the units under study get destroyed while testing.
Sample method:
In
this method, the information is obtained only from a part of the population
assuming that it is the population assuming that it is the representative of
the whole. Thus, in this method, a part is studied and on that basis conclusion
is drawn for the entire population. For Eg: If we want to study about the
smoking habits of 5000 adults of a locality then we collect the information
from only 500 adults of them and find out their smoking habit. On the basis of
smoking habit of these 500 adults, we draw conclusion for the whole 5000
adults.
Merits of Sample method:
- This method is less expensive.
- This method is less time consuming.
- The detail information can be obtained because only a part of the universe is studied.
- In case of infinite population this method is suitable.
- This is better method of investigation if the items are totally destroyed while testing.
- This method is used to check the result obtained from census method.
Demerits of Sample method:
- If the sample selected from the population is not representative one, it may give the wrong conclusion.
- This method should be handled only by experts. Otherwise, the result will be misleading.
- The result obtained from this method may not be reliable due to the possibility of personal biases in sampling.
- Selection of sample size is difficult task.
Methods of Sampling:
There
are various methods of Sampling which are as follows:
Judgement or Deliberate Sampling:
In
this method, the choice of items in the sample depends upon the judgement of
the investigator. For Eg: If there are 80 Students in a class and teacher has
to select 20 Students for survey then the selection of 20 Students would depend
upon the judgement of Investigator.
Random Sampling:
In
this method, every unit of the universe has equal chance of being selected in
the sample because the selection of any unit depends on chance. Lottery method
can be used for random sampling.
Stratified Random Sampling:
In
this method, the universe is divided into different groups or strata according
to some characteristics. Then sample is selected at random from each group or
strata.
Systematic Sampling
This
method can be applied only if the complete list of items in the universe is
available. In this method, first the units are arranged in some systematic
order and then the sample unit is selected on the basis of sampling interval.
The sampling interval is calculated as,
K = N
n
Where,
K = Sampling interval
N
= Total no. of items
n
= No. of sample items.
For example: If
we have to select 8 persons out of 40, then
K = N
n
= 40
8
= 5 (Sampling interval)
Multi – Stage Sampling:
In
this method, sampling is carried out in various stages. First of all, the
population is divided into large sample units and a sample is taken at random.
Again these are further divided into smaller units and a sample is taken at
random. This process is repeated many times.
Diagrammatic and Graphic Representation of data:
Diagrams
and Graphs are nothing but the presentation of statistical data in the form of
geometrical figure like points, lines, bars, rectangles, circles, etc.
Rules of Constructing diagrams:
There
are certain rules for constructing diagrams which are as follows:
- Choice of diagram
- Selection of scale
- Proportion between width and height
- Neatness and cleanliness
- Title of the diagram (Heading)
- Index
Types of Diagrams:
Simple bar diagram:
A
simple bar diagram is used to present one variable only. For Eg: Production,
profit, sales, marks, etc. can be solved with the help of simple bar diagram.
It consists of set of equi–distance rectangle of equal width.
Sub – divided bar diagram:
A
sub – divided diagram is a diagram which is used to represent the various
components of the total. Here we have to keep the index.
Multiple bar diagram:
It
is used to present two or more sets related data. The different values of each
set are presented by drawing a lot of physically joined rectangles. Here the
different shades or colours are used to distinguish the bars of one type from the
other.
Pie – diagram:
A
pie – diagram is a diagram in the form of a circle whose area represents the
total value. It is used to show the relation between the components with one
another to the other.
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