Which chart type is used to summarize categorical data with statistics such as mean or percentages?

• A. Bar chart
• B. Line chart
• C. Histogram
• D. Scatter plot

Answer: (A)

Bar charts are used to summarize categorical data, with each category represented by a bar whose height shows the frequency or percentage in that category. This makes it easy to compare categories at a glance, and you can also display a statistic like a mean for a numeric variable within each category by using the bar height to represent that mean. For example, you might show the percentage of respondents in each gender category or the average score by group.

Line charts are for ordered or time-based data, tracking changes over time. Histograms display the distribution of a numeric variable, not categories. Scatter plots illustrate relationships between two numeric variables.