1. Ratios, Rates and Percents
Lesson 17
Ratios, Rates and Percents
Experimental Probability

2. Warm-Up Determine whether each probability is impossible, unlikely,
equally likely, likely or certain.
You roll a 6 on a number cube.
There is a 0.8 chance of rain today.
You close your eyes or blink your eyes at least once in the next five minutes.
There is a 0.4 chance that the temperature will be greater than 60 degrees today. Write this probability as a percent and a simplified fraction.

3. Experimental Probability
Target:
Find and interpret the experimental probability of an event.

4. Vocabulary Outcome: One possible result from an experiment or
probability event.
Sample Space: The set of all possible outcomes for an
event.
Trial: A single act of performing an experiment.
Experimental Probability: The ratio of the number of
times an event occurs to the
total number of trials.

5. Example 1 Abram had 2 red marbles and 1 white marble in a bag.
He chose the white marble. Identify the outcome and
show the sample space for this experiment.
Abram chose a white marble.
Outcome: white
The possible marbles Abram could have chosen are red, red or white.
Sample Space: {red, red, white}

6. Experimental Probability

7. Example 2a Nik took a jelly bean out of a bag without looking. He
recorded the color. He placed it back in the bag. He did
this several times. The results are shown in the table.
Find the total number of trials.
= 48 trials
Color
Red
Yellow
White
Green
Frequency 4 12 8 24

8. Example 2b Nik took a jelly bean out of a bag without looking. He
recorded the color. He placed it back in the bag. He did
this several times. The results are shown in the table.
Find the experimental probability his next jelly bean will
be red.
Color
Red
Yellow
White
Green
Frequency 4 12 8 24

9. Example 2c Nik took a jelly bean out of a bag without looking. He
recorded the color. He placed it back in the bag. He did
this several times. The results are shown in the table.
Find the experimental probability his next jelly bean will
be green.
Color
Red
Yellow
White
Green
Frequency 4 12 8 24

12. Exit Problems
Identify the sample space: Tom rolls a regular six- sided number cube.
Sherlock put his music player on random play. It chose the same song 3 out of the last 12 times it played a song. What is the experimental probability it will play the same song for its next selection?
Charlie made 4 out of 5 free throws at basketball practice today. What is the experimental probability he will make a free throw at the game tonight?

13. Communication Prompt
Suppose you entered a contest where you will throw bean bags through a hole in a piece of plywood as part of a fundraiser. On the day of the contest, you will throw the bean bag 100 times. Explain how you could create an experiment to predict how many tosses you will make without actually throwing the bean bag 100 times. Identify your outcomes, sample space, and number of trials.