Bar Charts, Frequency Distributions, and Histograms
Frequency Distributions, Bar Graphs, and Circle Graphs
The
frequency
of a particular event is the number of times that the event occurs. The
relative
frequency
is the proportion of observed responses in the category.
Example:
We asked the students what country their car is from (or no car) and make a
tally of the answers. Then we computed the frequency and relative frequency of each
category. The relative frequency is computed by dividing the frequency by the total
number of respondents. The following table summarizes.
Country Frequency
Relative
Frequency
US
6
0.3
Japan
7
0.35
Europe
2
0.1
Korea
1
0.05
None
4
0.2
Total
20
1
Below is a bar graph for the car data. The height represents the frequency. Notice that
the widths of the bars are always the same.
We make a
circle graph
often called a
pie chart
of this data by placing wedges in the
circle of proportionate size to the frequencies.
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View Full DocumentBelow is a
pie chart
the shows this data.
Histograms
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 Fall '08
 STAFF
 Histograms, Frequency, Bar chart, Histogram, relative frequency

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