Conditional Probability Changes the Reference Group

Use the numbered activities in order. The complete practice sheet is an alternative to the first three focused activities and is not repeated in this pack.
Keep the answer folder separate from student copies. Partner A and B cards contain complementary information; give each learner only their own card.

Learning goals:
- Calculate probabilities from an invented two-way table.

Before you begin:
Understand the words and representations introduced in the Explore activity.

Teaching steps:
1. Begin with: How many parts are flagged?
2. Connect the response to: Among flagged parts, what fraction are defective?
3. Ask students to apply the idea: Why are the last two fractions different?

Watch for: Accepting an answer without checking whether it uses the material and satisfies the requested relationship or criteria.

Activity order:
1. learn — conditional-probability-tables-learn
2. practice — conditional-probability-tables-practice
3. apply — conditional-probability-tables-apply

These activities provide evidence to discuss. Completion alone does not establish mastery.
Paper size and page numbers are preserved in each PDF. Use the matching Sheet ID when checking an answer key.
