Chapter 2: Displaying and Summarizing Categorical Data

• A frequency table displays counts of occurrences for different categories.
• A relative frequency table shows these counts as fractions, decimals, or percentages.
• Relative frequency is found by dividing a category’s count by the total count.
• The sum of all relative frequencies should always equal 1 (or 100%).

Each section follows the same learning progression: understand the concept, practice the skill, think like a statistician, then apply your learning to authentic data.

Whether learning independently or teaching a class, the learning path below is designed to help students master the concepts in this section. Page references below correspond to the Real World Statistics instructional system.

Step 1: Watch the lesson video

Watch the lesson video and take notes on the key ideas.

Step 2: Read the section

Read pages 26-28 to reinforce the concepts introduced in the lesson.

Step 3: Practice what you've learned

Complete the 3 multi-part practice questions on pages 28-29. Check your work using the Answer Key, then review and correct any questions you missed before moving on.

Step 4: Think like a statistician
Explore Enrichment: Role-Based Statistical Analysis Tasks and the Chapter Dataset to apply statistical thinking in real-world contexts.

If you'd like additional guidance while working through the practice questions, explore the Worked Solutions Manual for step-by-step solutions and explanations.

Examples of authentic statistical work supported by this section include:

• organizing raw categorical responses (e.g., survey answers, preferences, or selections) into frequency and relative frequency tables to reveal distribution patterns 
• summarizing 100+ individual categorical responses into structured comparative views that support interpretation and decision-making 
• using aggregated categorical data to write a brief evidence-based recommendation or summary for a real-world stakeholder (e.g., school, business, or program leader) 

You may use these ideas to design your own investigations or explore the Real World Statistics System.

Enrichment: Role-Based Statistical Analysis Tasks place students in the role of a statistician working on real research problems, where they evaluate data, justify decisions, and communicate findings clearly. Each section includes multiple enrichment tasks, including one with a model response that demonstrates statistical reasoning in context, showing how evidence is evaluated, decisions are justified, and conclusions are communicated. This serves as a bridge to working with authentic datasets and independent statistical investigation within each chapter.

Available in the Interactive eBook at the end of the section (page 29) and in the Appendix of the Print Book (page 401).

Teaching with Real World Statistics: These structured learning paths—including Enrichment tasks and Chapter Datasets—can be adapted or copied directly into Canvas, Google Classroom, Schoology, and other learning management systems to simplify lesson planning and student assignments.