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Chapter 1: Introduction and Graphical Displays
17
Section Review
1-2 Frequency Distributions
One of the ways of summarizing and displaying real data is by means of a
table with the corresponding frequencies for individual values or interval of
values. Such tables are called
frequency distributions
.
Definition: Frequency Distribution
A frequency distribution is an organization of raw data into tabular form,
using classes (individual values or intervals) and frequencies.
The types of frequency distributions which we will deal with are
categorical
,
ungrouped
or
discrete
,
and
grouped
frequency distributions.
Definition: Frequency or Frequency Count
A frequency or the frequency count for a data set is the number of times that
a particular value occurs in the data set.
Categorical or Qualitative Frequency Distributions
Recall that we indicated that there were two types of variables. These were
broadly classified as qualitative (categorical) and quantitative variables.
When the variable is categorical or qualitative and we need to create a
frequency distribution for the data of that variable, we usually refer to the
resulting table as a qualitative frequency distribution.
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