Conditional Probability with Two-Way Tables

11th GradeMath50 min

Learning Objective

I can calculate conditional probabilities using two-way tables.

Lesson Flow

Watch Video

5 min

Ex: Find Conditional Probability Using a Table

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Guided Notes

10 min

Key concepts students will learn:

  • Conditional probability is the probability of an event occurring, given that another event has already occurred.

  • To find the probability that a selected student would be female given they received an A on the test, you can divide the number of female students who received an A by the total number of students who received an A.

  • The formula for conditional probability is P(E₂|E₁) = P(E₂ and E₁) / P(E₁), where E₂ is the event we're interested in and E₁ is the given event.

Practice

15 min

12 questions • Short answer

Exit Ticket

5 min

In a class of students, some play sports and some are in the math club. The table below summarizes the data: | | Math Club | Not in Math Club | Total | |------------|-----------|--------------------|-------| | Plays Sports | 15 | 25 | 40 | | Doesn't Play Sports | 10 | 20 | 30 | | Total | 25 | 45 | 70 | If a student is selected at random, what is the probability that they play sports, given that they are in the math club? Express your answer as a simplified fraction.

Teacher Guide

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  • Answer keys for all questions
  • Differentiation strategies
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