Exploring Two-Way Tables in Probability

This video tutorial explains how to use two-way tables to calculate probabilities. It begins with an introduction to two-way tables, followed by a step-by-step guide on setting up and completing a table using a survey example. The video then demonstrates how to calculate probabilities from the completed table, emphasizing the importance of understanding the group from which data is drawn. The tutorial concludes with examples of probability questions and their solutions.

What is the purpose of a two-way table?

• To graph data points

• To calculate complex equations

• To store data in a hierarchical format

• To compare two different variables

How many students preferred football?

• 54

• 33

• 87

• 68

What is the total number of teachers surveyed?

• 33

• 69

• 55

• 101

How many people in total preferred croquet?

• 101

• 87

• 55

• 68

What is the total number of students surveyed?

• 54

• 68

• 33

• 87

How many teachers preferred football?

• 54

• 33

• 68

• 87

If a student is chosen at random, what is the probability they preferred football?

• 68/101

• 1/156

• 54/87

• 33/87

If someone who prefers football is picked at random, what is the probability they are a teacher?

• 33/87

• 54/87

• 68/101

• 1/156

What is the total number of people surveyed?

• 156

• 101

• 87

• 214

If a person is picked at random from the survey, what is the probability they are a teacher who prefers croquet?

• 1/101

• 1/69

• 1/156

• 1/55