11-6 Experimental Probability
Preview
Warm Up
California Standards
Lesson Presentation
Holt CA Course 1
11-6 Experimental Probability
Warm Up
Use the table to find the probability of
each event.
1. A or B occurring 0.494
2. C not occurring 0.742
3. A, D, or E occurring
0.588
Holt CA Course 1
11-6 Experimental Probability
California
Standards
Review of Grade 6 SDAP3.2 Use data
to estimate the probability of future
events (e.g., batting averages or
number of accidents per mile driven).
Also covered:
6SDAP3.3
Holt CA Course 1
11-6 Experimental Probability
Vocabulary
experimental probability
Holt CA Course 1
11-6 Experimental Probability
In experimental probability, the likelihood of
an event is estimated by repeating an
experiment many times and observing the
number of times the event happens. That
number is divided by the total number of trials.
The more times the experiment is repeated, the
more accurate the estimate is likely to be.
Holt CA Course 1
11-6 Experimental Probability
Additional Example 1A: Estimating the Probability
of an Event
A marble is randomly drawn out of a bag and
then replaced. The table shows the results
after fifty draws.
Estimate the probability of drawing a red marble.
Outcome
Draw
probability 
Green
Red
Yellow
12
15
23
number of red marbles drawn = 15
total number of marbles drawn 50
The probability of drawing a red marble is about 0.3,
or 30%.
Holt CA Course 1
11-6 Experimental Probability
Additional Example 1B: Estimating the Probability
of an Event
A marble is randomly drawn out of a bag and
then replaced. The table shows the results
after fifty draws.
Estimate the probability of drawing a green
marble.
Outcome Green
Red
Yellow
Draw
probability 
12
15
23
number of green marbles drawn = 12
50
total number of marbles drawn
The probability of drawing a green marble is about
0.24, or 24%.
Holt CA Course 1
11-6 Experimental Probability
Additional Example 1C: Estimating the Probability
of an Event
A marble is randomly drawn out of a bag and
then replaced. The table shows the results
after fifty draws.
Estimate the probability of drawing a yellow
marble.
Outcome Green
Red
Yellow
Draw
probability 
12
15
23
number of yellow marbles drawn = 23
50
total number of marbles drawn
The probability of drawing a yellow marble is about
0.46, or 46%.
Holt CA Course 1
11-6 Experimental Probability
Check It Out! Example 1A
A ticket is randomly drawn out of a bag and
then replaced. The table shows the results
after 100 draws.
Estimate the probability of drawing a purple
ticket.
Outcome
Purple
Orange
Brown
Draw
55
22
23
probability 
number of purple tickets drawn = 55
100
total number of tickets drawn
The probability of drawing a purple ticket is about
0.55, or 55%.
Holt CA Course 1
11-6 Experimental Probability
Check It Out! Example 1B
A ticket is randomly drawn out of a bag and
then replaced. The table shows the results
after 100 draws.
Estimate the probability of drawing a brown
ticket.
Outcome
Purple
Orange
Brown
Draw
55
22
23
probability 
number of brown tickets drawn = 23
100
total number of tickets drawn
The probability of drawing a brown ticket is about
0.23, or 23%.
Holt CA Course 1
11-6 Experimental Probability
Check It Out! Example 1C
A ticket is randomly drawn out of a bag and
then replaced. The table shows the results
after 1000 draws.
Estimate the probability of drawing a blue
ticket.
Outcome
Red
Blue
Pink
Draw
probability 
285
112
603
number of blue tickets drawn = 112
1000
total number of tickets drawn
The probability of drawing a blue ticket is about
0.112, or 11.2%.
Holt CA Course 1
11-6 Experimental Probability
Additional Example 2: Sports Application
Use the table to compare the probability
that the Huskies will win their next game
with the probability that the Knights will
win their next game.
Holt CA Course 1
11-6 Experimental Probability
Additional Example 2 Continued
probability 
number of wins
total number of games
probability for a Huskies win  79  0.572
138
probability for a Knights win  90  0.616
146
The Knights are more likely to win their next
game than the Huskies.
Holt CA Course 1
11-6 Experimental Probability
Check It Out! Example 2
Use the table to compare the probability
that the Huskies will win their next game
with the probability that the Cougars will
win their next game.
Holt CA Course 1
11-6 Experimental Probability
Check It Out! Example 2 Continued
probability 
number of wins
total number of games
probability for a Huskies win  79  0.572
138
probability for a Cougars win  85  0.567
150
The Huskies are more likely to win their next
game than the Cougars.
Holt CA Course 1
11-6 Experimental Probability
Lesson Quiz: Part I
1. Of 425,234 seniors were enrolled in a math
course. Estimate the probability that a
randomly selected senior is enrolled in a
math course. 0.55, or 55%
2. Mason made a hit 34 out of his last 125
times at bat. Estimate the probability that he
will make a hit his next time at bat.
0.27, or 27%
Holt CA Course 1
11-6 Experimental Probability
Lesson Quiz: Part II
3. Christina polled 176 students about their
favorite yogurt flavor. 63 students’ favorite
flavor is vanilla and 40 students’ favorite
flavor is strawberry. Compare the probability
of a student’s liking vanilla to a student’s
liking strawberry.
about 36% to about 23%
Holt CA Course 1