2. What is statistics
It is the branch of mathematics that deals with the
collection, organization, analysis, and interpretation
of numerical data.
Statistics is especially useful in drawing general
conclusions about a set of data from a sample of the
data.
3. Statistics in Plural Sense
The word Statistics in plural sense are the
numerical observations collected for some definite
purpose regarding some field of study.
For example statistics of wages, statistics of prices,
statistics of births, statistics of deaths, statistics of
marriages.
4. Statistics in Singular Sense
Statistics in singular sense is a body of methods used
in the collection, presentation, analysis and
interpretation of data.
5. What is the purpose of statistics
Statistics teaches people to use a limited sample to make
intelligent and accurate conclusions about a greater
population.
The use of tables, graphs, and charts play a vital role in
presenting the data being used to draw these conclusions.
For example
Consumer goods are daily used products, the
businessman use statistics to calculate which consumer
goods are available in the store and which are not.
6. What are the types of statistics
The field of statistics is divided into two major
divisions.
1-descriptive statistics and
2- Inferential statistics
7. Descriptive statistics
Descriptive statistics deals with the presentation
and collection of data. This is usually the first part
of a statistical analysis.
Inferential statistics
As the name suggests, involves drawing the right
conclusions from the statistical analysis that has
been performed using descriptive statistics.
8. Limitation of Statistics
1)Statistics is not study the qualitative phenomenon statistics,
being a science dealing with a set of numerical data.
2)Statistics does not study individuals. Statistics deals with
an aggregate of objects.
3)Statistical laws are not exact as the law of physical and
natural sciences. Statistical laws are only approximations.
4) Statistics is liable to be misused, it must be used by
experts.
9. Observation
In statistics, numerical measure of some condition is
called an observation. Observation serve as raw
material for statistical work, we take observations
by counting or by measurement.
For example the number of workers in different
factories are counted and their blood-pressures are
measured.
10. Population
A collection of all the elements we are studying and
about which we are trying to draw conclusions.
Population can be finite or infinite.
1) Population of children in secondary school.(finite)
2) Population of patients in hospitals. (finite)
3) Population of books in a library. (finite)
4) Population of fish in an ocean. (infinite)
5) Population of stars in a galaxy. (infinite)
11. Sample
A collection of some, but not all, of the elements of
the population under study, used to describe the
population.
OR
A small part of a population is called sample.
12. Parameter
Any measure of the population is called a parameter.
Parameter is a fixed quantity.
For example
Population Arithmetic mean is called a Parameter.
Statistic
Any measure of the sample is called statistic.
Statistic is a variable quantity.
For example
Sample Arithmetic mean is called a Statistic.
