Chapter 3: Displaying and Summarizing Quantitative Data

• Stem-and-leaf displays help us to visualize quantitative data while preserving actual values.
• The stem represents the leading digits, while the leaf shows the trailing digits.
• Unlike histograms, stem-and-leaf displays are best suited for smaller datasets.
• A key is used to define the meaning of the stems and leaves.

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 68-71 to reinforce the concepts introduced in the lesson.

Step 3: Practice what you've learned

Complete the 4 practice questions on pages 72. 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 quantitative measurements into stem-and-leaf displays to examine distributions (e.g., a rehabilitation clinic analyst summarizing patient recovery times, or a school district researcher organizing student assessment scores) 
• interpreting stem-and-leaf displays to describe clusters, gaps, typical values, and overall spread (e.g., a public health analyst examining residents' daily step counts, or an environmental scientist reviewing household water consumption records) 
• comparing two quantitative distributions using matching stem-and-leaf displays to support recommendations (e.g., a hospital data analyst evaluating emergency room wait times across two locations, or a manufacturing quality specialist comparing production times between two facilities) 

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 72) 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.