There are three coins defined in the Fair Coins Starter File: coin1, coin2, and coin3.

One of these coins is fair, one will land on "heads" 75% of the time, and one will land on "heads" 90% of the time. Which one is which?

1 In the table below, record five flips of each coin and the number of "heads" you saw. Then convert that number into a percentage. Finally, write a "Y" or "N" depending on whether you think each coin is fair based on your sample.

Sample coin1 coin2 coin3

1

2

3

4

5

#heads

/5

/5

/5

% heads

%

%

%

fair?

2 In the table below, record 15 more flips of each coin and the number of "heads" you saw. Then convert that number into a percentage. Finally, write a "Y" or "N" depending on whether you think each coin is fair based on your sample.

Sample coin1 coin2 coin3

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

#heads

/20

/20

/20

% heads

%

%

%

fair?

3 Which weighted coin did you identify first: fair, 75%, or 90%?

4 Why was that coin the easiest to find?

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