is it better to guess? - weebly

Chapter 17 Skills Practice • 961

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Is It Better to Guess?Using Models for Probability

VocabularyChoose a term from the box to complete each sentence.

probability model uniform probability model non-uniform probability model

1. A is a list of each possible outcome along with its probability.

2. When all probabilities in a probability model are the same, it is called a

.

3. When all probabilities in a probability model are not the same, it is called a

.

Problem SetConstruct a probability model for each situation. Determine whether the model is a uniform probability

model or a non-uniform probability model.

1. Roll a 10-sided number polyhedron.

Outcome 1 2 3 4 5 6 7 8 9 10

Probability 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1

P(1) 5 1 ___ 10

, or 0.1

The model is a uniform probability model.

Lesson 17.1 Skills Practice

Name _______________________________________________________Date _________________________

962 • Chapter 17 Skills Practice

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Lesson 17.1 Skills Practice page 2

2. Randomly select a painted rock from a bag containing 4 purple rocks, 3 green rocks, 3 orange

rocks, and 2 blue rocks.

Outcome

Probability

3. Spin a spinner with 8 numbered sections of equal size.

Outcome

Probability


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Name ________________________________________________________ Date _________________________

4. Randomly select 1 of 5 members of your hockey team to take the first shot in an overtime

shootout.

Outcome

Probability

5. Spin a spinner with colored sections of equal size. The spinner has 3 blue sections, 3 red sections,

and 2 yellow sections.

Outcome

Probability


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6. Randomly select a female member of the Math Club whose members are Marcus, Isabella,

Jasmine, Levi, Joseph, Belinda, Catherine, James, and Julia.

Outcome

Probability

Use the probability model to answer each question.

Outcome 1 2 3 4 5 6 7 8

Probability 2 ___ 25

4 ___ 25

1 ___ 25

5 ___ 25

2 ___ 25

4 ___

25 3 ___

25 4 ___

25

7. What is the probability of an outcome of 4?

P(4) 5   5 ___ 25

  

The probability of an outcome of 4 is   5 ___ 25

  .

8. What is the probability of an outcome of 7?


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Name ________________________________________________________ Date _________________________

9. What is the probability of an outcome that is less than 6?

10. What is the probability of an outcome that is greater than 8?

11. What is the probability of an outcome that is an odd number?

12. What is the probability of an outcome that is less than 10?


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Use the probability model to answer each question.

Outcome A B C D E F


5 ___ 20

2 ___ 20

7 ___ 20

1 ___ 20

3 ___ 20

13. What is the probability of an outcome of B?

14. What is the probability of an outcome of F?

15. What is the probability of an outcome that is not C?


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Name ________________________________________________________ Date _________________________

16. What is the probability of an outcome that is a consonant?

17. What is the probability of an outcome that is not A?

18. What is the probability of an outcome that is a vowel?


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Three Girls and No Boys?Creating and Using Probability Models

VocabularyDefine each term in your own words.

1. tree diagram

2. complementary events

Problem SetList all of the possible outcomes for each problem situation. Complete the probability model using all

the possible outcomes.

1. What is the probability that the first 3 students that enter a classroom are boys? List all of the

possible outcomes for the first 3 students entering the classroom. Complete the probability model.

Possible outcomes: BBB, BBG, BGB, BGG, GGG, GGB, GBG, GBB

Outcome 0 boys 1 boy 2 boys 3 boys

Probability 1 __ 8 3 __

8 3 __

8 1 __

8

The probability that the first 3 students that enter the classroom are boys is 1 __ 8

.


Name ________________________________________________________ Date _________________________


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2. You toss a coin 2 times. What is the probability that both tosses result in heads? List all of the

possible outcomes for the 2 coin tosses. Complete the probability model.

Outcome 0 Heads 1 Heads 2 Heads

Probability

3. A spinner has 2 equal parts. One part is blue; one part is white. What is the probability that

spinning the spinner 3 times will result in only 1 blue result? List all of the possible outcomes for

the 3 spins. Complete the probability model.

Outcome 0 blue 1 blue 2 blue 3 blue

Probability

4. A spinner has 3 equal parts. One part is red, one part is blue, and one part is yellow. What is the

probability that spinning the spinner 2 times will result in 2 yellow results? List all of the possible

outcomes of the 2 spins. Complete the probability model.

Outcome 0 yellow 1 yellow 2 yellow

Probability


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Name ________________________________________________________ Date _________________________

5. A bag contains a purple stone, a yellow stone, and an orange stone. A stone is randomly chosen

from the bag, the stone’s color is recorded and the stone is replaced in the bag. If you choose a

stone from the bag 2 times, what is the probability that only 1 of the chosen stones is purple? List

all of the possible outcomes of choosing 2 stones. Complete the probability model.

Outcome 0 purple 1 purple 2 purple

Probability

6. A six-sided number cube has two faces with a 1, two faces with a 2, and two faces with a 3. It

is tossed 2 times. What is the probability that both tosses result in a 1? List all of the possible

outcomes of tossing the number cube 2 times. Complete the probability model.

Outcome Zero 1s One 1 Two 1s

Probability


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Complete the tree diagram to determine the possible outcomes for each problem situation. Complete

the probability model.

7. What is the probability that the first 4 students that enter a classroom are girls? Complete the tree

diagram to determine all of the possible outcomes for the first 4 students entering the classroom.

Complete the probability model.

Boy

Boy

Boy

B G B G B G B G

Girl

Girl Boy Girl

Girl

Boy

Boy

B G B G B G B G

Girl

Girl Boy Girl

1st

2nd

3rd

4th

Outcome 0 girls 1 girl 2 girls 3 girls 4 girls


4 ___ 16

6 ___ 16

4 ___ 16

1 ___ 16

The probability that the first 4 students to enter the classroom are girls is 1 ___ 16

.


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Name ________________________________________________________ Date _________________________

8. You toss a coin 4 times. What is the probability that all 4 tosses result in heads? Complete the

tree diagram to determine all of the possible outcomes for the 4 coin tosses. Complete the

probability model.

H T1st

2nd

3rd

4th

Outcome 0 heads 1 heads 2 heads 3 heads 4 heads

Probability


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9. A spinner has 3 equal parts. One part is green, one part is orange, and one part is yellow. What is

the probability that spinning the spinner 3 times will result in 0 orange results? Complete the tree

diagram to determine all of the possible outcomes of the 3 spins. Complete the probability model.

Green Orange Yellow1st

2nd

3rd

Outcome 0 orange 1 orange 2 orange 3 orange

Probability

10. A six-sided number cube has two faces with a 1, two faces with a 2, and two faces with a 3. It is

tossed 3 times. What is the probability that all 3 tosses result in a 1? Complete the tree diagram

to determine all of the possible outcomes of tossing the number cube 3 times. Complete the

probability model.

1 2 31st

2nd

3rd

Outcome Zero 1s One 1 Two 1s Three 1s

Probability


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Name ________________________________________________________ Date _________________________

11. A bag contains a red stone, a yellow stone, and a blue stone. A stone is randomly chosen from the bag,

the stone’s color is recorded and the stone is replaced in the bag. If you choose a stone from the bag

2 times, what is the probability that only 1 of the chosen stones is blue? Complete the tree diagram to

determine all of the possible outcomes of choosing 2 stones. Complete the probability model.

Red Yellow Blue1st

2nd

Outcome 0 blue 1 blue 2 blue

Probability

12. A spinner has 4 equal parts. One part is black, one part is white, one part is red, and one part is yellow.

What is the probability that spinning the spinner 2 times will result in 2 red results? Complete the tree

diagram to determine all of the possible outcomes of the 2 spins. Complete the probability model.

1st

2nd

Black White Red Yellow

Outcome 0 red 1 red 2 red

Probability


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Identify a complementary event.

13. A coin is tossed 1 time. The probability that tossing the coin will result in heads is P(heads). What

is a complementary event?

P(tails)

14. A spinner has 2 equal parts. One part is blue, one part is white. The probability that spinning the

spinner will result in blue is P(blue). What is a complementary event?

15. A six-sided number cube is rolled. The probability that the result is less than 3 is P(less than 3).

What is a complementary event?

16. A letter between A and E is chosen. The probability that the result is A is P(A). What is a

complementary event?

17. A letter between A and E is chosen. The probability that the result is a vowel is P(vowel). What is a


18. A letter between A and E is chosen. The probability that the result is not D is P(not D). What is a



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Name ________________________________________________________ Date _________________________

Pet Shop ProbabilityDetermining Compound Probability

VocabularyDefine the term in your own words.

1. compound event

Problem SetDetermine each probability using the probability table.

A spinner has 6 parts labeled with the letters A through F. The probability table shows the probability

of spinning each letter on the next spin.

A

CD

F

E B

Outcome A B C D E F

Probability 1 __ 6

1 __ 6

1 __ 6

1 __ 6

1 __ 6

1 __ 6

1. What is the probability that the next spin is an A or B?

P(A or B) 5 P(A) 1 P(B)

5 1 __ 6 1 1 __

6

5 2 __ 6

5 1 __ 3


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2. What is the probability that the next spin is a vowel?

3. What is the probability that the next spin is not C?

4. What is the probability that the next spin is a consonant?


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Name ________________________________________________________ Date _________________________

5. What is the probability that the next spin is a D, E, or F?

6. What is the probability that the next spin is not an A or B?


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Marbles were placed in two buckets. The first bucket contains 1 marble of each of the following colors:

red, blue, green. The second bucket contains 1 marble of each of the following colors: yellow, green,

purple, blue.

R B G Y G P B

7. Determine the possible outcomes for choosing 1 marble from each bucket.

RY, RG, RP, RB

BY, BG, BP, BB

GY, GG, GP, GB

8. What is the probability of choosing 2 unique colors?

9. What is the probability of choosing green from the first bucket and green from the second bucket?


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Name ________________________________________________________ Date _________________________

10. What is the probability of choosing blue from the first bucket or blue from the second bucket?

11. What is the probability of choosing red from the first bucket or yellow from the second bucket?

12. What is the probability of choosing the same color from each bucket?


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A game requires spinning a spinner numbered 1 through 5 and rolling a six-sided number cube.

1

2

34

5

13. Determine the possible outcomes for playing the game.

21 3 4 5

1 2 3 4 5 6 1 2 3 4 5 6 1 2 3 4 5 6 1 2 3 4 5 6 1 2 3 4 5 6

Spinner

Number Cube

14. What is the probability of spinning an even number and rolling an even number?

15. What is the probability of spinning an odd number and rolling an odd number?


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Name ________________________________________________________ Date _________________________

16. What is the probability of spinning a number less than 4 or rolling a number less than 4?

17. What is the probability of spinning a number greater than 3 or rolling a number greater than 3?


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18. What is the probability of spinning a 5 or rolling a 5?

19. What is the probability of spinning a 6 or rolling a 6?


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What Type of Blood Do You Have?Simulating Probability of Compound Events

Problem SetPerform a simulation to determine each probability.

1. The preferences of customers at a local movie rental store are given in the table. Perform a

simulation to determine the probability that out of the next 5 customers to rent a movie, at least 1

rents a comedy.

Movie Type Comedy Drama Science Documentary

Percent of Customers

31% 42% 22% 5%

Sample answer.

Assign the numbers 00 to 30 to the people who rent a Comedy movie.

Assign the numbers 31 to 72 to the people who rent a Drama movie.

Assign the numbers 73 to 94 to the people who rent a Science Fiction movie.

Assign the numbers 95 to 99 to the people who rent a Documentary.


Name ________________________________________________________ Date _________________________


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Trial Number NumbersNumber of Customers Who Rent

a Comedy

1 65, 28, 59, 71, 12 2

2 13, 85, 30, 10, 94 3

3 11, 58, 38, 16, 56 2

4 10, 04, 43, 51, 61 2

5 20, 17, 26, 45, 27 4

6 38, 22, 93, 01, 18 3

7 16, 43, 81, 09, 97 2

8 66, 56, 92, 98, 56 0

9 95, 50, 95, 63, 97 0

10 54, 31, 19, 99, 25 2

Out of the 10 trials, 8 trials had at least 1 customer rent a comedy.

P(at least 1 customer rents a comedy) 5 8 ___ 10

5 0.8


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Name ________________________________________________________ Date _________________________

2. A survey at a middle school asked students their hair color. The percentage of students with each

hair color is shown in the table. Perform a simulation to determine how many students will enter

the building before a student with blond hair enters the building.

Hair Color Brown Blond Red

Percent of Students

71% 23% 6%


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Trial Number NumbersNumber of Students to Enter the Building Before A Blond Student


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Name ________________________________________________________ Date _________________________

3. A survey at a middle school asked students to choose their favorite sport to watch on TV. The

percentage of students who prefer each sport is shown in the table. Perform a simulation to determine

the probability that out of the next 5 students to enter the building, at least 1 prefers hockey.

Sport Football Baseball Basketball Hockey

Percent of Students

32% 30% 26% 12%


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Name ________________________________________________________ Date _________________________

4. The kicker of the high school football team makes 4 out of every 6 field goal attempts. What is the

probability that the kicker will successfully make the next 2 field goals? Perform a simulation to

determine the probability.

Trial Number NumbersNumber of Successful Field

Goal Attempts


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5. The attendant at a parking garage notices that typically 2 out of every 6 cars that enter the parking

garage are white. Perform a simulation to determine how many cars will enter the parking garage

before a white car enters the parking garage.

Trial Number NumbersNumber of Cars to Enter the

Parking Lot Before A White Car


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Name ________________________________________________________ Date _________________________

6. At a bakery, 3 out of 5 customers who enter the bakery prefer banana nut muffins to the other

flavors available. Perform a simulation to determine how many customers will enter the bakery

before a customer who prefers banana nut muffins enters the bakery.

Trial Number NumbersNumber of Customers to Enter

the Bakery Before A Customer Who Prefers Banana Nut Muffins

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