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Chapter 3: Measures of Variability
Solution:
We can use the
Basic Statistics
workbook to verify the
following results.
Data Set A:
= 11, Mean = 10;
= 30.9091
Data Set B:
= 11, Mean = 10;
= 4.9091
Figure 3-11
shows dot plots for the data with the means and
s.
Figure 3-11:
Dot plot display with the means and
the
MAD
s
for
Example 3-7
Observe that Data Set A has the larger
. Also, observe that
Data Set A is much variable about the mean than Data Set B. Thus one can
infer that if the means are equal for two different data sets of equal sample
sizes, then the data set with the larger
will be much more variable
about the mean. This is the case because the absolute deviations for Data
Set A are much larger than the absolute deviations for Data Set B. Thus, one
can see from this discussion that the
is indeed a measure of variability.