In the next preview assignment and in the next class, you will need to understand how to read a contingency table and compute probabilities.
We use a contingency table, sometimes called a two-way table, to organize data on two categorical variables at the same time. Today we are going to look at a fun example that will help us lay a strong foundation for probability and help us get know each other a little bit better.
Basic Probability (AND, OR)
Question 1
Do you like to eat sweets? If so, what are some of your favorites?
Question 2
Complete the following table using data from your class and the questions as a guide.
- How many students are present in class today? Add this number in the appropriate cell on the table.
Do you like chocolate chip cookies? Do you like oatmeal raisin cookies?
Yes No Total Yes No Total - How many students in class today answered “yes” to the question: “Do you like chocolate chip cookies?” Add this number in the appropriate cell on the table.
- How many students in class today answered “yes” to the question: “Do you like oatmeal raisin cookies?” Add this number in the appropriate cell on the table.
- Complete the Total row and Total column.
Question 3
Describe the student cookie preferences of the highlighted cells using complete sentences.
- Do you like chocolate chip cookies? Do you like oatmeal raisin cookies?
Yes No Total Yes No Total - Do you like chocolate chip cookies? Do you like oatmeal raisin cookies?
Yes No Total Yes No Total
Question 4
Work with your group to decide on a strategy to determine the remaining values in the table you started in Question 2.
Question 5
You are asked: “How many students like oatmeal raisin cookies OR chocolate chip cookies?” Your friend suggests that you add the total number of “yes” answers to both questions. What is wrong with this strategy?
Question 6
Calculate the number of students that like oatmeal raisin cookies OR chocolate chip cookies.
