Chapter 3 · Displaying and Summarizing Quantitative Data

Section 3.9Descriptive Statistics with the TI-84

The TI-84 calculator is a powerful tool for computing descriptive statistics quickly and accurately. In this section, you'll learn how to enter data using lists or frequency tables and retrieve key statistics — including the mean, median, standard deviation, and five-number summary — in just a few keystrokes.

Summary

Data entryData can be entered into the TI-84 using lists (for raw data) or frequency tables (for grouped data), both accessed through the STAT menu.

1-Var StatsThe 1-Var Stats command computes all key descriptive statistics at once, including the mean, median, standard deviation, and five-number summary.

Mean and standard deviationThe calculator reports both the sample standard deviation (Sx) and the population standard deviation (σx) — choosing the correct one depends on whether the data represents a sample or the full population.

Five-number summaryThe TI-84 outputs the minimum, Q1, median, Q3, and maximum directly, making it easy to construct box plots and assess the spread of a dataset.

Using technology to compute statistics efficiently is a core skill in modern data analysis — understanding what the calculator outputs, and when each statistic is appropriate, is just as important as knowing how to compute it by hand.

The Real World Statistics Learning Progression

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

Learn This Section

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

Read the sectionRead pages 106–111 to reinforce the calculator steps introduced in the videos.

Practice what you've learnedComplete the practice questions on page 111. Check your work using the Answer Key, then review and correct any questions you missed before moving on.

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

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

From Learners to Statisticians

Examples of authentic statistical work supported by this section include:

Using the TI-84 to compute descriptive statistics for a dataset of student test scores, then interpreting the mean, median, and standard deviation to describe the class's overall performance and identify any unusual results (e.g., a teacher preparing a data-driven progress report for a department meeting).
Entering frequency table data into the TI-84 to efficiently compute the five-number summary for a large grouped dataset, then using those values to construct a box plot and assess the spread of the distribution (e.g., a public health analyst summarizing patient age distributions from a clinical study).
Comparing the sample standard deviation (Sx) and population standard deviation (σx) outputs to determine which measure is appropriate for a given research context, and explaining the distinction in a written statistical report (e.g., a student researcher analyzing survey data from a sample of participants).

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

Enrichment: Role-Based Statistical Analysis Tasks

Enrichment 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 111) 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.

Part of the Real World Statistics instructional system — bringing together print, interactive learning, videos, datasets, enrichment, worked solutions, and teacher resources.