CK-12-Basic Probability and Statistics Concepts - A Full Course

3.6. Theoretical and Experimental Coin Tosses http://www.ck12.org

Example C

2 fair coins are tossed 10 times. What is the theoretical probability of both coins landing on heads? What is the
experimental probability of both coins landing on heads?

The theoretical probability of getting heads on the first coin is^12. Flipping the second coin, the theoretical probability

of getting heads is again^12. The overall theoretical probability is

( 1

2

) 2

for 2 coins, or:

P( 2 H) =

1

2

×

1

2

P( 2 H) =

(

1

2

) 2

P( 2 H) =

1

4

To determine the experimental probability, let’s go to the probability simulator. Again, you can also do this
experiment manually by taking 2 coins, tossing them 10 times, and recording your observations.

Choose Toss Coins and then choose SET by pressing

ZOOM

.

Choose OK by pressing

GRAPH

and go back to the main screen. Then choose TOSS by pressing

WINDOW

.