Conditional Probability in Venn Diagrams

1. Conditional Probability in Venn Diagrams Slideshow 59, Mathematics Mr Richard Sasaki, Room 307

2. Recall how to insert data into Venn Diagrams Find probabilities in Venn Diagrams and understand how conditions affect them Objectives

3. We know how to use Venn Diagrams now (this is our third lesson). Introduction Set A Set B The total number of values in this diagram is the number of entries surveyed.

4. If we choose one of the entries surveyed at random, we can find the probability of it being in its given category. Probabilities Example 50 Total # of entries: Set A Set B

5. Firstly I’d like us to do a shading in exercise. Shade in the areas mentioned on your worksheet. Shading Exercise Answers

6. Do you know the meaning of conditional probability? Conditional Probability It means how the chance of something changes depending on whether something else happened or not. For this we use given that which has a ‘|’ symbol. What does B given that A mean? ( Set A Set B It means that A has already happened. We’re only interested in set A. So what is the new probability of B?

7. Conditional Probability Example 50 Total # of entries: Set A Set B Try the worksheet please!

8. (A) (A) Set A Set B Set A Set B Set C