Page 106 - IM_Algebra1_FL Print Sample.pdf

3. Explain or show why there appears to be an association for the rst pair of variables and why there appears to be no association for the other pair of variables.
4. Prepare a display of your work to share.
Student Response
Answers vary. Sample response:
1. Associated: High school grade and starting or not starting on a sports team. Not associated: Saltwater or freshwater tank and decorations or not in the tank.
2.
starting
not starting
9th or 10th grade
10
30
11th or 12th grade
40
20
decorations
no decorations
saltwater tank
30
20
freshwater tank
32
18
Unit 3
Lesson 3: Associations in Categorical Data 39
3. In the rst table, there is an association since most of the 9th or 10th graders do not start, but most of the 11th or 12th graders do. In the second table there appears to be no association since the row relative frequencies are very close for each type of tank. About 60% of saltwater tanks have decorations and 64% of freshwater tanks do, too. These are very close.
Activity Synthesis
The goal is to make sure students understand when there is a possible association and when there is no association in categorical data.
Invite each group to present its chosen variable pairs. After each group presents, discuss how the group created the data for each two-way table and how others can recognize if there is an association present or not. If time permits, ask questions such as:
• “Was one table easier to create than the other? Why?” (The data with no association was more di cult to create because i had to think about getting the relative frequencies similar.)
• “What was the most challenging part of this task?” (It was challenging to gure out how to create a table that shows an association because I had several categories for each variable.)
• “What insight into two-way tables, relative frequencies, or associations in categorical data did you gain as a result of doing this task?” (First, this really got me thinking about categorical data because I kept thinking about numerical data and that did not work. Second, it really helped me understand why we needed relative frequencies and not just the frequencies from the