8. What is meant by the term central tendency? Why is the central tendency an incomplete
summarization of a variable?
The typical response is referred to as the “central tendency,” and there are two measures of
9. When summarizing a categorical variable, what is the proper measure of central tendency,
and why is it the proper measure? What is the proper measure of variability and why?
The proper measure is the mode because with categorical variables, one should only count
the number of times (or percentage of times) that the category occurs. The proper variability
10. When summarizing a metric variable, what is the proper measure of central tendency, and
why is it the proper measure?
11. Describe how a percentage distribution is computed.
Frequencies themselves are raw counts, and these frequencies are easily converted into per-
centages for ease of comparison. The conversion is arrived at very simply through a quick
12. When summarizing a metric variable, what is the most informative measure of variability,
and why is it the most informative measure?
The most informative measure is the standard deviation (as opposed to the range—minimum
and maximum) because the standard deviation is computed by explicitly comparing every
13. Describe how a standard deviation is computed.
The standard deviation indicates the degree variability in the metric values in such a way as
to be translatable into a normal or bell-shaped curve distribution. Calculate the average, then