The distribution of a categorical variable is

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Unformatted text preview: age start with graphs. Then add numerical summaries. Distributions v༇ Distribution of a variable What possible values the variable takes and how frequently it takes those values. There are many methods to describe and display distributions. Distributions of Categorical Variables The values of a categorical variable are the labels for the categories. The distribution of a categorical variable is described by either the count or the percent of individuals who fall in each category. Example: BUAD310: Class Composition [2 sections taken together] CLASS LEVEL U1 U2 U3 U4 Count 43 57 33 13 Percent 29.452 39.041 22.603 8.904 Graphs for Categorical Variables v༇  In the bar chart the height of each bar is proportional to the count (or percent) in each category Graphs for Categorical Variables v༇  In the pie chart the area of each piece is proportional to the percent of individuals in each category Bar charts and Pie charts •  Bar chart is called a Pareto chart when the categories are sorted by frequency (popular in quality control). •  Pie charts are commonly chosen to illustrate market shares or sources of revenue for a company. •  Pie charts are less useful than bar charts if we want to compare actual counts (easier to compare bars than angles of wedges). Bar charts and Pie charts BUAD310: Student Composition Bar charts and Pie charts BUAD310: Student Composition Correct Charts & the Area Principle •  The area occupied by a part of the graph/chart that displays data should be proportional to the amount of data it represents. •  Charts decorated to attract attention often violate the area principl...
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