A bar graph displays the number of students in four different majors: Biology, Chemistry, Physics, and Mathematics. Which statement best summarizes the data this bar graph shows?

• A. The bar graph is best for showing how a variable changes over time.
• B. The bar graph is used to display the relationship between two continuous variables.
• C. The bar graph compares the frequencies of students across different categorical majors, making it suitable for visualizing qualitative data.
• D. The bar graph shows the distribution of students' test scores, which are quantitative data.

Answer: (C)

Verified step by step guidance

1. Step 1: Understand the purpose of a bar graph. A bar graph is typically used to compare the frequencies or counts of different categories, which are qualitative or categorical data.
2. Step 2: Identify the type of data being displayed. In this problem, the data represent the number of students in different majors (Biology, Chemistry, Physics, Mathematics), which are categories rather than numerical measurements.
3. Step 3: Recognize that bar graphs are not ideal for showing changes over time or relationships between continuous variables. Those purposes are better served by line graphs or scatter plots, respectively.
4. Step 4: Evaluate each statement given in the problem to see which one correctly describes the use of a bar graph with categorical data. The correct statement should mention comparing frequencies across categories.
5. Step 5: Conclude that the best summary is that the bar graph compares the frequencies of students across different categorical majors, making it suitable for visualizing qualitative data.