10-2 Experimental Probability
Warm Up
Problem of the Day
Lesson Presentation
Course 2
10-2 Experimental Probability
Warm Up
1. A jar contains 6 red, 8 blue, and 10 white
marbles. Would you be more likely to pull out a red
blue
or a blue marble?
Determine if the event is impossible, unlikely,
as likely as not, likely, or certain.
2. Attendance at a city council meeting is at 100%.
Mr. Lloyd is a council member. How likely is it that
Mr. Lloyd is at the meeting?
certain
Course 2
10-2 Experimental Probability
Problem of the Day
The probability of Liana making a free
2
throw was 3 . If she made 24 of her free
throws, how many did she miss?
12
Course 2
10-2 Experimental Probability
Learn to find experimental probability.
Course 2
10-2 Experimental
Insert LessonProbability
Title Here
Vocabulary
experimental probability
Course 2
10-2 Experimental Probability
Experimental probability is one way of estimating
the probability of an event. The experimental
probability of the event is found by comparing
the number of times an event occurs to the total
number of trials. The more trials you have, the
more accurate the estimate is likely to be.
Course 2
10-2 Experimental Probability
EXPERIMENTAL PROBABILITY
probability  number of times an event occurs
total number of trials
Course 2
10-2 Experimental Probability
Additional Example 1: Sports Application
During skating practice, Sasha landed 7 out
of 12 jumps. What is the experimental
probability that she will land her next jump?
P(event)  number of times an event occurs
total number of trials
number of jumps landed
P(jumps landed)  number
of jumps attempted
= 7 Substitute data from the experiment.
12
The experimental probability that Sasha will land her
next jump is 7 .
12
Course 2
10-2 Experimental Probability
Writing Math
“P(event)” represents the probability that an event
will occur. For example, the probability of a flipped
coin landing heads up could be written as “P(heads).”
Course 2
10-2 Insert
Lesson Probability
Title Here
Experimental
Check It Out: Example 1
During basketball practice, Martha made 9 out of
10 free throws. What is the experimental
probability that she will make her next attempt?
P(event)  number of times an event occurs
total number of trials
number of free throws made
P(free throws made) 
number of free throws attempted
9 = 90% Substitute data from the
= 10
experiment and write as a percent.
The experimental probability that Martha will make the
next free throw is 9 or 90%.
10
Course 2
10-2 Experimental Probability
Additional Example 2A: Application
Students have checked out 55 books from the
library. Of these, 32 books are fiction.
What is the experimental probability that
the next book checked out will be fiction?
number of fiction books checked out
P(fiction)  total number of books checked out
 32
55
Substitute data.
The experimental probability that the next book
checked out will be fiction is approximately 32.
55
Course 2
10-2 Experimental Probability
Additional Example 2B: Application
What is the experimental probability that
the next book checked out will be nonfiction?
of nonfiction books checked out
P(nonfiction)  number
total number of books checked out
 23
Substitute data.
55
The experimental probability that the next book checked
out will be nonfiction is approximately 23.
55
Course 2
10-2 Insert
Lesson Probability
Title Here
Experimental
Check It Out: Example 2A
Students have a fruit choice for lunch of an
apple or a pear. So far 18 of 47 students have
selected pears.
What is the experimental probability that the
next fruit selected will be a pear?
P(pear) 
number of pears selected
total number of fruit selected
 18
47
Substitute data.
The experimental probability that the next fruit
selected will be a pear is approximately 18.
47
Course 2
10-2 Insert
Lesson Probability
Title Here
Experimental
Check It Out: Example 2B
What is the experimental probability that
next fruit selected will be an apple?
number of apples selected
P(apple)  total number of fruit selected

29 Substitute data.
47
The experimental probability that the next fruit
selected will be an apple is approximately 29 .
47
Course 2
10-2 Experimental
Insert LessonProbability
Title Here
Lesson Quiz
1. In a soccer shoot-out, Bryan made 4 out of 9
goals. What is the experimental probability that
4
he will make the next shot?
9
2. It has rained on the last 2 out of 10 Fourth of
July parades in Swanton.
A. What is the experimental probability that it
1
will rain this year on July 4? 5
B. What is the experimental probability that it
4
will not rain this year?
5
Course 2