1. Section 5.5 - Independent Events
Andy (A), Bob (B), and Charlie (C) take turns rolling a fair die. Find the probability that Charlie rolls a five before Andy or Bob.

2. Section 5.5 - Independent Events
Andy (A), Bob (B), and Charlie (C) take turns rolling a fair die. Find the probability that Charlie rolls a five before Andy or Bob.

3. Section 5.5 - Independent Events
Andy (A), Bob (B), and Charlie (C) take turns rolling a fair die. Find the probability that Charlie rolls a five before Andy or Bob.

4. Section 5.5 - Independent Events
P37. Suppose you select one person at random from the Titanic passengers and crew. Use the definition of independent events to determine whether the events “didn’t survive” and “male” are independent. Are any two events in this table independent?
Display 5.39
Gender
Male
Female
Total
Survived?
Yes
367
344
711 No
1364
126
1490
1731
470
2201

5. Section 5.5 - Independent Events
P37. Determine whether the events “didn’t survive” and “male” are independent. Are any two events in this table independent?
Display 5.39
Gender
Male
Female
Total
Survived?
Yes
0.2120
0.7319
0.3230 No
0.7880
0.2681
0.6770
1.0000

6. Section 5.5 - Independent Events
P38. Suppose you draw a card at random from a standard deck. Use the definition of independent events to determine which pairs of events are independent.
Getting a heart; Getting a jack
Getting a heart; Getting a red card
Getting a 7; Getting a heart

7. Section 5.5 - Independent Events
P38. Suppose you draw a card at random from a standard deck. Use the definition of independent events to determine which pairs of events are independent.
Getting a heart; Getting a jack
Getting a heart; Getting a red card
Getting a 7; Getting a heart

8. Section 5.5 - Independent Events
P39. About 42% of people have type O blood. Suppose you select two people at random and check whether they have type O blood.
Make a table to show all possible results.
What is the probability that exactly one of the two people has type O blood?
Make a tree diagram that illustrates the situation.

9. Section 5.5 - Independent Events
P39. Make a table to show all possible results.
Second Person O
Not O
Total
First Person
0.1764
0.2436
0.4200
0.3364
0.5800
1.0000

10. Section 5.5 - Independent Events
P39. Make a table to show all possible results.
What is the probability that exactly one of the two people has type O blood?
Second Person O
Not O
Total
First Person
0.1764
0.2436
0.4200
0.3364
0.5800
1.0000

11. Section 5.5 - Independent Events
P39. Make a table to show all possible results.
What is the probability that exactly one of the two people has type O blood?
Second Person O
Not O
Total
First Person
0.1764
0.2436
0.4200
0.3364
0.5800
1.0000

12. Section 5.5 - Independent Events
P39. Make a tree diagram that illustrates the situation.

13. Section 5.5 - Independent Events
P40. Suppose you select ten people at random. Using the information in P39, find the probability that
at least one of them has type O blood
at least one of them doesn’t have type O blood

14. Section 5.5 - Independent Events
P40. Suppose you select ten people at random. Using the information in P39, find the probability that
at least one of them has type O blood
Second Person O
Not O
Total
First Person
0.1764
0.2436
0.4200
0.3364
0.5800
1.0000

15. Section 5.5 - Independent Events
P40. Suppose you select ten people at random. Using the information in P39, find the probability that
at least one of them doesn’t have type O blood
Second Person O
Not O
Total
First Person
0.1764
0.2436
0.4200
0.3364
0.5800
1.0000

16. Section 5.5 - Independent Events
P41. After taking college placement tests, freshmen sometimes are required to repeat high school work. Such work is called “remediation” and does not count toward a college degree. About 11% of college freshmen have to take a remedial course in reading. Suppose you select two freshmen at random and check to see if they have to take remedial reading.
Find the probability that both freshmen have to take remedial reading.
Show how to use a two-way table to find the probability that exactly one freshman needs to take remedial reading
Show how to use a tree-diagram to answer the question in part b.

17. Section 5.5 - Independent Events
P41a. About 11% of college freshmen have to take a remedial course in reading. Suppose you select two freshmen at random and check to see if they have to take remedial reading.
Find the probability that both freshmen have to take remedial reading.

18. Section 5.5 - Independent Events
P41b. Show how to use a two-way table to find the probability that exactly one freshman needs to take remedial reading
Second Freshman
Needs RR
Doesn’t
Total
First Freshman
0.0121
0.0979
0.1100
0.7921
0.8900
1.0000

19. Section 5.5 - Independent Events
P41c. Show how to use a tree-diagram to answer the question in part b.

20. Section 5.5 - Independent Events
E58. Use the definition of independent events to determine which of these pairs of events are independent when you roll two dice.
Rolling doubles; rolling a sum of 8
Rolling a sum of 8; getting a 2 on the first die rolled
Rolling a sum of 7; getting a 1 on the first die rolled
Rolling doubles; rolling a sum of 7
Rolling a 1 on the first die; rolling a 1 on the second die

21. Section 5.5 - Independent Events
E58. Use the definition of independent events to determine which of these pairs of events are independent when you roll two dice.
Rolling doubles; rolling a sum of 8
Rolling a sum of 8; getting a 2 on the first die rolled
Rolling a sum of 7; getting a 1 on the first die rolled
Rolling doubles; rolling a sum of 7
Rolling a 1 on the first die; rolling a 1 on the second die

22. Section 5.5 - Independent Events
E64. Schizophrenia affects 1% of the U.S. population and tends to first appear between the ages of 18 and 25. Today, schizophrenia accounts for the fifth highest number of years of work lost due to disability among Americans aged Fewer than 30% of people with this illness are currently employed.
Suppose you select a person from the U.S. population at random.
State whether each question can be answered using the information given. If the question can be answered, answer it.

23. Section 5.5 - Independent Events
E64. Schizophrenia affects 1% of the U.S. population and tends to first appear between the ages of 18 and 25. Today, schizophrenia accounts for the fifth highest number of years of work lost due to disability among Americans ages Fewer than 30% of people with this illness are currently employed.
What is the probability that the person is schizophrenic?
What is the probability that the person is unemployed?
What is the probability that the person is unemployed and schizophrenic?
What is the probability that the person is unemployed or schizophrenic?
What is the probability that the person is unemployed given that he is schizophrenic?
What is the probability that he is schizophrenic given that he is unemployed?

24. Section 5.5 - Independent Events
E64. Schizophrenia affects 1% of the U.S. population and tends to first appear between the ages of 18 and 25. Today, schizophrenia accounts for the fifth highest number of years of work lost due to disability among Americans ages Fewer than 30% of people with this illness are currently employed.
Schizophrenic?
Yes No
Total
Employed?
0.003
0.007
0.010
0.990
1.000

25. Section 5.5 - Independent Events
E64. Schizophrenia
What is the probability that the person is schizophrenic?
What is the probability that the person is unemployed?
What is the probability that the person is unemployed and schizophrenic?
What is the probability that the person is unemployed or schizophrenic?
What is the probability that the person is unemployed given that he is schizophrenic?
What is the probability that he is schizophrenic given that he is unemployed?
Schizophrenic?
Yes No
Total
Employed?
0.003
0.007
0.010
0.990
1.000

26. Section 5.5 - Independent Events
E64. Schizophrenia affects 1% of the U.S. population and tends to first appear between the ages of 18 and 25. Today, schizophrenia accounts for the fifth highest number of years of work lost due to disability among Americans ages Fewer than 30% of people with this illness are currently employed.
What is the probability that the person is schizophrenic? 0.01
What is the probability that the person is unemployed? Can’t be determined
What is the probability that the person is unemployed and schizophrenic? 0.007
What is the probability that the person is unemployed or schizophrenic? Can’t be determined
What is the probability that the person is unemployed given that he is schizophrenic? More than 0.70
What is the probability that he is schizophrenic given that he is unemployed? Can’t be determined

27. Section 5.5 - Independent Events
E66. A committee of three students is to be formed from six juniors and five seniors. If three names are drawn at random, what is the probability that the committee will consist of all juniors or all seniors?

28. Section 5.5 - Independent Events
E66. A committee of three students is to be formed from six juniors and five seniors. If three names are drawn at random, what is the probability that the committee will consist of all juniors or all seniors?

29. Section 5.5 - Independent Events
E66. A committee of three students is to be formed from six juniors and five seniors. If three names are drawn at random, what is the probability that the committee will consist of all juniors or all seniors?

30. Section 5.5 - Independent Events
E70. Joaquin computes the probability that if two dice are rolled, then exactly one die will show a 4 as:
Joaquin is wrong. What did he forget?

31. Section 5.5 - Independent Events
E70. Joaquin computes the probability that if two dice are rolled, then exactly one die will show a 4 as:
Joaquin is wrong. What did he forget?

32. Section 5.5 - Independent Events
sometimes is called the law of total probability.
Prove the law of total probability
Use this law to find P(Dodgers win) from the information in Display 5.51.
Prove Bayes’ Theorem:
Use Bayes’ Theorem to find P(Dodgers win|day game)

33. Section 5.5 - Independent Events
sometimes is called the law of total probability.
Prove the law of total probability B B’ A
A  B
A  B’ A’

34. Section 5.5 - Independent Events
sometimes is called the law of total probability.
Use this law to find P(Dodgers win) from the information in Display 5.51.
Won the Game?
Yes No
Total
Time of Game
Day 11 10 21
Night 30 27 57 41 37 78

35. Section 5.5 - Independent Events
sometimes is called the law of total probability.
Use this law to find P(Dodgers win) from the information in Display 5.51.
Won the Game?
Yes No
Total
Time of Game
Day 11 10 21
Night 30 27 57 41 37 78

36. Section 5.5 - Independent Events
E75. Prove Bayes’ Theorem

37. Section 5.5 - Independent Events
E75. Use Bayes’ Theorem to find P(Dodgers win|day game)
Won the Game?
Yes No
Total
Time of Game
Day 11 10 21
Night 30 27 57 41 37 78

38. Section 5.5 - Independent Events
E75. Use Bayes’ Theorem to find P(Dodgers win|day game)
Won the Game?
Yes No
Total
Time of Game
Day 11 10 21
Night 30 27 57 41 37 78

39. Section 5.5 - Independent Events
E75. Use Bayes’ Theorem to find P(Dodgers win|day game)
Won the Game?
Yes No
Total
Time of Game
Day 11 10 21
Night 30 27 57 41 37 78