Which of the following would not be a valid way to summarize or visualize a categorical variable?

• A. A frequency table
• B. A pie chart
• C. A histogram
• D. A bar chart

Answer: (C)

Verified step by step guidance

1. Step 1: Understand what a categorical variable is. A categorical variable represents data sorted into categories or groups, such as colors, types, or labels, rather than numerical values.
2. Step 2: Review common methods to summarize or visualize categorical data. These include frequency tables, pie charts, and bar charts, all of which display counts or proportions of categories clearly.
3. Step 3: Recognize that a histogram is designed for numerical data, showing the distribution of continuous variables by grouping data into intervals (bins) and plotting frequencies.
4. Step 4: Compare the options given: frequency tables, pie charts, and bar charts are appropriate for categorical data, while histograms are not suitable because they require numerical, continuous data.
5. Step 5: Conclude that the invalid method for summarizing or visualizing a categorical variable is the histogram, as it does not effectively represent categorical data.