Math Clip Art

The Probability Tour

 

Grade 8 - Memorial Middle School - Beverly, MA

 

The Birthday Problem

 

1. Read the introduction and then scroll down to the simulation.

2. Choose the numbers you want to try in the first part of the experiment and write them in column 2 below.

3. Type in the class size and hit return or enter to view the random list of birthdays and the number of matches (10 trials each).

4. Record the number of matches in column 3 below.(separated by commas)

range class size number of matches
1 - 10    
11 - 20    
11 - 20    
21 - 30    
21 - 30    
21 - 30    
31 - 40    
31 - 40    
31 - 40    
40 - 50    

 

5. Now scroll up to the top of the "birthdays" page and click on

    EXPLANATION.

6. Read the explanation and examine the graph.  This is a graph of

    the probability of having two people in a room with the same

    birthday.

7. How many people need to be in a room to have a probability of

    50% of having the same birthday, according to the graph? ____

    How many people for a 90% chance?  ____

8. Now go back to the "birthdays" page and scroll down to the                                                                                                     

    simulation and try these numbers.

class size number of matches
45  
46  
47  
48  
49  
50  

 

9. Did you always get at least 1 match? ______

    Explain why.__________________________________________

 

CONCLUSION:

 

 

{Teacher's}    {Probability Tour}    {Birthday Problem}    {Probable Pen}    {Back To DI Math}

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