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Chapter 15: Chi-Square Tests
Section Review
15-3 The Chi-Square Test for Goodness-of-Fit
Have you ever wondered whether a sample of observed data (frequency or
relative frequency distribution, proportions or percentages) fits some pattern
or distribution? We should not expect the observed pattern to exactly fit a
given distribution, so we can look for differences and make conclusions as to
the
goodness-of-fit
of the data to the distribution.
For example, in
Figure 15-7
, one can clearly see that the pattern of the
sample data does not quite follow the pattern or distribution of the
population. As a matter of fact, the sample data deviates quite severely from
the pattern or population distribution. Hence one may intuitively conclude
in this example that the sample data may not have come from the population
to which it is compared because of the large deviations of the sample
distribution to that of the population distribution.
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