# Lesson 1

Two-way Tables

• Let’s look at categorical data.

### Problem 1

This two-way table shows the results of asking students if they prefer to have gym class in the morning or the afternoon.

morning afternoon total
total 45 55 100
1. How many students participated in the survey?
2. How many students in grade 8 prefer to have gym in the morning?
3. How many grade 10 students participated in the survey?
4. How many students prefer to have gym in the afternoon?

### Problem 2

A random sample of adults are asked about their preferences for a first dinner date with someone. Complete the two-way table so that it has the characteristics listed.

• 122 people responded to the survey.
• 50 of the people who said they order dessert said they also prefer to split the check.
• 68 people prefer splitting the check.
• 56 people prefer to skip dessert rather than ordering one.
order dessert no dessert
split the check
one person pays

### Problem 3

Students in the 7th, 8th, and 9th grade were asked whether they prefer to write in pen or pencil.

• 40 students prefer to write in pen.
• 60 students prefer to write in pencil.

Create values that could represent the number of students in the 7th, 8th, and 9th grade that responded to the survey.

### Problem 4

A recent study observed the number of bike riders ages 0 to 20 that wear helmets. The results are represented in the table.

wear helmet did not wear helmet
0-5 years 21 4
6-10 years 34 14
11-15 years 14 18
16-20 years 3 12

Make an observation based on a data value that is not in the table. Explain your reasoning.