Lesson 2
Statistical Questions
Lesson Narrative
In this lesson, students continue to analyze questions and the kinds of responses they can expect from those questions. They begin to recognize variability in data and learn about statistical questions and how they differ from nonstatistical questions. In order to define variability, students categorize data sets and name the categories to make use of structure (MP7) because they are seeking mathematically important similarities between the objects.
Learning Goals
Teacher Facing
 Justify (orally) whether a question is “statistical” based on whether variability is expected in the data that could be collected.
 Match survey questions to data sets representing possible responses and justify (in writing) why they match.
Student Facing
Let's look more closely at data and the questions they can help to answer.
Required Materials
Required Preparation
Prior to the warmup, prepare a large class dot plot for the class to use with a horizontal axis labeled "pencil length (inches)" and intervals of \(\frac{1}{4}\) from 0 to 8.
One dot sticker for each student to include in the class dot plot.
Prior to the What Makes a Statistical Question activity, prepare a twocolumn table to record students' observations and display for all to see.
Print and cut up cards from the Sifting for Statistical Questions blackline master. Prepare 1 set of cards for every 2 students.
Learning Targets
Student Facing
 I can tell when data has variability.
CCSS Standards
Glossary Entries

categorical data
A set of categorical data has values that are words instead of numbers.
For example, Han asks 5 friends to name their favorite color. Their answers are: blue, blue, green, blue, orange.

dot plot
A dot plot is a way to represent data on a number line. Each time a value appears in the data set, we put another dot above that number on the number line.
For example, in this dot plot there are three dots above the 9. This means that three different plants had a height of 9 cm.

numerical data
A set of numerical data has values that are numbers.
For example, Han lists the ages of people in his family: 7, 10, 12, 36, 40, 67.

statistical question
A statistical question can be answered by collecting data that has variability. Here are some examples of statistical questions:
 Who is the most popular musical artist at your school?
 When do students in your class typically eat dinner?
 Which classroom in your school has the most books?

variability
Variability means having different values.
For example, data set B has more variability than data set A. Data set B has many different values, while data set A has more of the same values.