| 5.1.1 |
What is statistics? |
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The collection, processing, interpretation,
and presentation of numerical data all belong to the domain of statistics.
The word "statistics" is used in several ways. It can refer not only
to the mere tabulation of numeric information, but also to the body of
techniques used in processing or analysing data. |
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| 5.1.2 |
Descriptive statistics |
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A data set in its original form
is usually very large. Consequently, such a data set is not very
helpful in drawing conclusions or making decisions. It is easier
to draw conclusions from summary tables and diagrams than from the original
version of a data set. Therefore, it is usually reduce data to a manageable
size by constructing tables, drawing graphs, or calculating summary measures
such as averages. Methods that helps us to do this type of statistical
analysis is called descriptive statistics. |
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| 5.1.3 |
Population and sample |
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A population is a collection of
all the elements we are studying and about which we are trying to draw
conclusions.
A sample is a collection of some,
but not all, of the elements of the population. |
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| 5.1.4 |
Parameter and statistic |
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A parameter is a characteristic
of a population.
A statistic is a characteristic
of a sample. |
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