1. Experimental Probability
Key information:
Definition: Probability based on experimental data
# of times an event occurs
P(event) =
# of times an experiment is done

2. a.) P(Pink) = b.) P(Green) =
1.) Use the table below to answer the following 
questions. Write each probability as a fraction in lowest 
terms.
Color
Number of Ipods 12
Pink
Green 8
Blue 28
a.) P(Pink) =   b.) P(Green) =
c.) P(Blue) =  d.) P(green or pink)

3. 2.) In-class experiment: Flipping a Coin
Directions:
Flip the electronic coin 25 times as a class
Record the number of times it lands on heads or tails
Before you begin, use the theoretical probability to
predict the number of times it will come up heads.
Theoretical Probability: P(heads) =

4. Use tallies to record the results.
Heads
Tails
Experimental Probability: P(heads) =
Critical thinking:
1.) Was the experimental probability the same as the theoretical 
probability?
2.) If we flipped the coin 1,000,000 times, , what do you think 
would happen to the experimental probability compared to the theoretical probability?

5. What is the difference between experimental 
probability and theoretical probability?
Theoretical Probability: what "should" happen
Experimental Probability: what "did" happen
Important Note: Both can be used to predict future events

6. 3.) A reporter surveys 125 people to determine whether they 
plan to vote for or against a proposed bill. Of these people, 100 
say they plan to vote for the bill.
a.) What is the experimental probability that the
next person surveyed would vote for the bill?
Write as a fraction in lowest terms.
b.) What is the experimental probability that the
next person surveyed would not vote for the bill?

7. The line plot shows the days of the week for students' birthdays in Ms
The line plot shows the days of the week for 
students' birthdays in Ms. Wilson's homeroom.
1.) How many students are in Ms. Wilson's homeroom?
2.) P(Sunday) 3.) P(Wednesday)
4.) P(weekday) 5.) P(Weekend)

8. Demonstrate Understanding:
1.) Tonya made 36 saves on 50 shots. What is the 
experimental probability that she will make a save on the 
next shot? Write answer as a percent and a fraction in lowest terms.
2.) A medical study tests a new medicine on 20 people. It is 
effective on 18 of them. Find the experimental probability 
that the medicine is effective. Write answer as a percent 
and as a fraction in lowest terms.