1. Approximately, 1/3 of our population CANNOT roll their tongue
According to which source you use, the percentage is between
19 and 35%

2. SIDE BAR:
Rolling of tongue has a different set of statistics than other tongue tricks like:
Clover Tongue
Flip Tongue

3. Please take 30 seconds to show your table partner your fancy tricks with your tongue
We have
math to learn

4. Consider This:
Ria is doing a survey on the number of people with different genetic traits
She asks people, one at time, if they can roll their tongues.
Ria was surprised that she asked 5 people before she found someone who wasn’t able to roll their tongue?

5. Does this mean:
The statement “approximately 1 our of 3 people are not able to roll their tongue” is false?
Is it unusual that after surveying 5 people she did not find anyone who could not roll their tongue?

6. To answer this question
We will do a simulation of Ria’s experiment
Slips of paper
Rolling dice
Spinning a wheel
Drawing cards
Software that generates random numbers
Simulate a 1 out of 3 chance

7. Simulation
What is the number of times it takes to roll a 1 or 2 with a die?
Make the following table on a full sheet of paper

8. Number of attempts 1 2 3 4 5 6 7 8 9 10
Record a Talley
Combined Results (60 simulations)
% out of 60 simulations

9. Each Person Rolls Own Die
Roll the die until you get a 1 or 2
Keep rolling until you get 1 or 2 twenty times
Tally how many times you need to roll to get 1 or 2
Number of attempts 1 2 3 4 5 6 7 8 9 10
Record a Talley
Combined Results (60 simulations)
% out of 60 simulations

10. Combine Data with 2 Other People
Put your combined results in the row marked, “Combined Results (60 simulations)”
Number of attempts 1 2 3 4 5 6 7 8 9 10
Record a Talley
Combined Results (60 simulations) 20 13
% out of 60 simulations

11. Calculate the % Out of 60 Simulations
Number of attempts 1 2 3 4 5
Record a Talley
Combined Results (60 simulations) 20 13 9 6
% out of 60 simulations
20/60
33%
13/60
23%

12. What is the probability it would take five or more attempts?
(Add the probability of 5-10 in the bottom row)
Theoretically, it should be around 11/60
How does your experimental probability compare with the theoretical probability?
Were Ria’s results unusual? Write 5 sentences to explain why or why not.