Deck 6: Probability

Question 1

A researcher wanted to compare eye color distributions of babies born with a birth defect with babies who did not have the birth defect.26 babies with the defect were matched on gender,race,and age with 52 babies without the defect.The frequency of different eye colors as a function of the presence or absence of the defects was as follows:
Eye Color
Group Dark Medium Light
Defect 1 6 19
No Defect 15 13 24
What is the probability that a baby has dark eyes given that the baby has the birth defect?

A).04
B).06
C).01
D).61

Answer 1

.04

Question 2

The statement "Given that a person is satisfied with his job,what is the probability that he is satisfied with his marriage?" is an example of a(n):

A)hypothesis
B)conditional probability
C)independent event
D)a and c

Answer 2

conditional probability

Question 3

In probability theory,when two outcomes cannot occur simultaneously they are ____.

A)conditional probabilities
B)mutually exclusive
C)mutually exhaustive
D)exhaustive

Answer 3

mutually exclusive

Question 4

In a population consisting of 60 males and 40 females,the probability of randomly selecting a male is:

A)6%
B).06
C).60
D)undefined

Question 5

A researcher wanted to compare eye color distributions of babies born with a birth defect with babies who did not have the birth defect.26 babies with the defect were matched on gender,race,and age with 52 babies without the defect.The frequency of different eye colors as a function of the presence or absence of the defects was as follows:
Eye Color
Group Dark Medium Light
Defect 1 6 19
No Defect 15 13 24
The probability of the number of observations favoring both events A and B,divided by the total number of observations,is called a ____ probability.

A)conditional
B)binomial
C)joint
D)simple

Question 6

A researcher wanted to compare eye color distributions of babies born with a birth defect with babies who did not have the birth defect.26 babies with the defect were matched on gender,race,and age with 52 babies without the defect.The frequency of different eye colors as a function of the presence or absence of the defects was as follows:
Eye Color
Group Dark Medium Light
Defect 1 6 19
No Defect 15 13 24
The values entered within the table (that is,1,6,19,15,13,24)are called ____.

A)cell frequencies
B)marginal frequencies
C)unit frequencies
D)cell probabilities

Question 7

The outcome of a trial according to probability theory is a(n)_____.

A)conditional probability
B)marginal frequency
C)event
D)joint probability

Question 8

According to the classical view of probability theory,the probability of event A equals .____.

A)the number of total observations/the number of events favoring A
B)The number of events favoring A/the total number of possible observations
C)the number of events favoring A
D)1 - the number of events favoring A/the total number of possible events

Question 9

A researcher wanted to compare eye color distributions of babies born with a birth defect with babies who did not have the birth defect.26 babies with the defect were matched on gender,race,and age with 52 babies without the defect.The frequency of different eye colors as a function of the presence or absence of the defects was as follows:
Eye Color
Group Dark Medium Light
Defect 1 6 19
No Defect 15 13 24
The marginal frequencies for eye color are

A)26 and 52
B)16,19,43
C)78
D)156

Question 10

A researcher wanted to compare eye color distributions of babies born with a birth defect with babies who did not have the birth defect.26 babies with the defect were matched on gender,race,and age with 52 babies without the defect.The frequency of different eye colors as a function of the presence or absence of the defects was as follows:
Eye Color
Group Dark Medium Light
Defect 1 6 19
No Defect 15 13 24
A ____ probability indicates the likelihood that an event will occur given that some other event occurs.

A)joint
B)conditional
C)simple
D)combination

Question 11

The probability of an event,A,is formally defined as the number of observations favoring event A divided by the:

A)total number of possible observations
B)total number of possible events
C)proportion of observations
D)proportion of events

Question 12

The probability of observing at least one of two events [for example,p(A or B)] is ____.

A)p(A,B)- p(A)
B)p(A,B)- p(B)
C)p(A)p(B)
D)p(A)+ p(B)- p(A,B)

Question 13

A researcher wanted to compare eye color distributions of babies born with a birth defect with babies who did not have the birth defect.26 babies with the defect were matched on gender,race,and age with 52 babies without the defect.The frequency of different eye colors as a function of the presence or absence of the defects was as follows:
Eye Color
Group Dark Medium Light
Defect 1 6 19
No Defect 15 13 24
If a baby were randomly selected from the study,what is the probability of that baby having light eyes?

A).43
B).19
C).24
D).55

Question 14

A _____ indicates the likelihood that an event will occur given that some other event occurs.

A)probability distribution
B)conditional probability
C)marginal probability
D)mutually exclusive probability

Question 15

Given a set of outcomes that are mutually exclusive and exhaustive,the sum of the probabilities of the outcomes will always equal:

A)100
B).01
C).10
D)1.0

Question 16

A researcher wanted to compare eye color distributions of babies born with a birth defect with babies who did not have the birth defect.26 babies with the defect were matched on gender,race,and age with 52 babies without the defect.The frequency of different eye colors as a function of the presence or absence of the defects was as follows:
Eye Color
Group Dark Medium Light
Defect 1 6 19
No Defect 15 13 24
If a baby was randomly selected from those participating in the study,the likelihood of that baby having dark eyes is ____.

A)1/16
B)35/78
C)16/78
D)1/26 + 15/52

Question 17

If events A and B are independent,then ____.

A)p(A|B)= p(A)
B)p(B|A)= p(A|B)
C)p(A)= (B)
D)none of these

Question 18

In the language of probability theory,the act of flipping a coin is called a(n)_____ and each unique outcome is called a(n)_____.

A)observation;trial
B)trial;event
C)event;observation
D)none of these

Question 19

Two outcomes are said to be _____ if it is impossible for both outcomes to occur simultaneously for a given individual.

A)mutually exclusive
B)mutually conditional
C)mutually distributed
D)mutually impossible

Question 20

Each unique combination of variables in a contingency table is referred to as a:

A)marginal frequency
B)expected value
C)column
D)cell

Question 21

The likelihood of observing each of two events is referred to as a:

A)hypothesis
B)binomial probability
C)conditional probability
D)joint probability

Question 22

Let event A be "satisfied with one's marriage" and event B be "satisfied with one's job.The probability that someone is satisfied with both his marriage and his job is equal to:

A)p(A|B)
B)p(A,B)
C)p(B)p(A|B)
D)b and c

Question 23

The probability that an individual is satisfied with his marriage (event A)and satisfied with his job (event B)is an example of
A _____.

A)joint probability
B)conditional probability
C)marginal probability
D)mutually exclusive probability

Question 24

Sampling without replacement causes the probability of randomly selecting additional cases from that population to____.

A)stay the same
B)increase
C)decrease

Question 25

A(n)_____ of a set of objects or events is an ordered sequence.

A)enumeration
B)combination
C)permutation
D)manipulation

Question 26

In a binomial probability calculation,there are ____ possible outcomes.

A)many
B)N!
C)two
D)N!/r!

Question 27

Even though two events are related (nonindependent),this does not necessarily mean that:

A)one is dependent on the other
B)one causes the other
C)the joint probability is 0
D)a and c

Question 28

Suppose you wanted a rat to learn a maze which included 3 choice points and each choice included 3 different directions.Assume only 1 choice can be correct at a time.What is the probability of a rat finding the goal without any errors?

A)3!
B)27
C)1/9
D).333³

Question 29

A permutation of a set of objects or events ____.

A)is an ordered sequence
B)is a sequence in which order doesn't matter
C)is a random selection of events
D)has fewer events than a combination

Question 30

Suppose you are asked to toss 10 dimes and observe the number of heads.What is the likelihood of observing exactly 0 heads?

A).001
B).50
C)0
D)1.0

Question 31

In the case of sampling _____,the outcome of the first random selection in no way affects the outcome of the second random selection.

A)without replacement
B)with replacement
C)with correction for continuity
D)without error

Question 32

In a horse race,people are allowed to bet on which horses will finish a race in positions 1,2,or 3.If the field contained 7 horses,how many ways can 3 horses finish in the three positions?

A)7!
B)210
C)35
D)3

Question 33

In general notation,the probability of observing at least one of event A and event B is:

A).50
B)p(A or B)= p(A)+ p(B)
C)p(A or B)= p(A)+ p(B)+ p(A,B)
D)p(A or B)= p(A)+ p(B)- p(A,B)

Question 34

Using the binomial expression to compute a probability requires ____.

A)a sequence of n independent trials
B)more than 2 outcomes
C)that the probability of success = .5
D)that the probability of failure = 0

Question 35

A set of objects that are arranged such that the internal order is irrelevant is called a ____.

A)combination
B)binomial root
C)permutation
D)simple event

Question 36

A counting rule that involves a set of objects of events in an ordered sequence is called a ____.

A)combination
B)conditional rule
C)binomial
D)permutation

Question 37

A combination of a set of objects or events is a sequence in which the internal ordering of elements is:

A)systematic
B)predetermined
C)important
D)irrelevant

Question 38

The process of randomly selecting a case,taking some measurement of interest,and then returning the case to the population is called:

A)sampling without replacement
B)sampling with replacement
C)sampling without error
D)sampling with error

Question 39

There are 6 students running for president at state college.The top 2 candidates are always declared winners and a run-off election is held to determine which of the two is the president.How many ways could 2 students be selected from among the first 6?

A)30
B)6!/2!
C)15
D)6³

Question 40

A therapist claims that a particular technique has been successful in the treatment of eating disorders.You find out that only 7 out of 10 clients were actually helped.What is the probability of observing 7 successes if the probability of success = .5?

A).7
B).5
C).117
D).77

Question 41

If p (A | B)= 0,then it follows that A and B must be

A)mutually exclusive
B)independent
C)factorial
D)both a and b

Question 42

If the probability of an experimental outcome that we observed was calculated to be less than .05 assuming the null hypothesis to be true,then we would ____.

A)accept the null hypothesis
B)reject the null hypothesis
C)fail to reject the null hypothesis
D)change the alpha level

Question 43

In factorial notation,the expression 6! equals:

A)6 factorial
B)(6)(5)(4)(3)(2)(1)= 720
C)a and b
D)neither a nor b

Question 44

A sample of 500 people aged 30 - 40 years old were interviewed to study the relationship between whether a person graduated from college or only high school and whether s/he changed jobs in the last 5 years.The results are found in the contingency table below.
Answers below have been rounded to two decimal places.
What is the probability that an individual has graduated from college?

A).36
B).49
C).51
D).64

Question 45

When the alpha level is .05,a result is defined as non-chance if the probability of obtaining that result,assuming the null hypothesis is true,is:

A)greater than .05
B)equal to .05
C)less than .05
D)none of these

Question 46

If the probability of event A is .40 and the probability of event B is .35,what is the probability that event A or B will occur,if A and B are independent?

A).14
B).61
C).75
D)cannot be determined

Question 47

A sample of 500 people aged 30 - 40 years old were interviewed to study the relationship between whether a person graduated from college or only high school and whether s/he changed jobs in the last 5 years.The results are found in the contingency table below.
Answers below have been rounded to two decimal places.
What is the probability that an individual has not changed jobs,given that they have graduated from high school only?

A).13
B).25
C).35
D).65

Question 48

A sample of 500 people aged 30 - 40 years old were interviewed to study the relationship between whether a person graduated from college or only high school and whether s/he changed jobs in the last 5 years.The results are found in the contingency table below.
Answers below have been rounded to two decimal places.
Which of the following is a marginal frequency in the above table?

A)63
B)128
C)245
D)500

Question 49

For small n,the correction for _____ yields even better correspondence between the binomial and normal distributions.

A)attenuation
B)continuity
C)small sample sizes
D)error

Question 50

A sample of 500 people aged 30 - 40 years old were interviewed to study the relationship between whether a person graduated from college or only high school and whether s/he changed jobs in the last 5 years.The results are found in the contingency table below.
Answers below have been rounded to two decimal places.
What is the probability that an individual has changed jobs and they have graduated from college?

A).20
B).26
C).40
D).52

Question 51

A sample of 500 people aged 30 - 40 years old were interviewed to study the relationship between whether a person graduated from college or only high school and whether s/he changed jobs in the last 5 years.The results are found in the contingency table below.
Answers below have been rounded to two decimal places.
What is the probability that an individual has changed jobs?

A).23
B).49
C).51
D).64

Question 52

If our observations are so discrepant from the expected result that the difference cannot be attributed to chance,we will _____ the null hypothesis.

A)accept
B)reject
C)revise
D)restate

Question 53

Determining what constitutes chance versus non-chance results under the assumption that the null hypothesis is true is done with reference to a probability value known as a(n):

A)conditional probability
B)beta level
C)binomial probability
D)alpha level

Question 54

Assuming the null hypothesis is true,we can specify an _____ of an investigation.

A)expected result
B)alternative result
C)improbable result
D)all of these

Question 55

A sample of 500 people aged 30 - 40 years old were interviewed to study the relationship between whether a person graduated from college or only high school and whether s/he changed jobs in the last 5 years.The results are found in the contingency table below.
Answers below have been rounded to two decimal places.What is the probability that an individual has changed jobs or they have graduated from college?

A).49
B).64
C).87
D)1.13

Question 56

The binomial and normal distributions are closely related,with the correspondence between them depending on the values of:

A)n and p
B)a and b
C)alpha and beta
D)the mean and standard deviation

Question 57

If the observed result of a study is similar enough to the outcome stated in the null hypothesis such that it can reasonably be attributed to chance,we will _____ the null hypothesis.

A)accept
B)reject
C)fail to reject
D)revise

Question 58

The correspondence between the binomial and normal distributions:

A)improves as p becomes closer to .50
B)improves as p becomes closer to .05
C)improves as n increases
D)a and c

Question 59

A biopsychologist is interested in how quickly rats learn a complicated maze.He puts 5 rats,labeled A,B,C,D,and E,in a box.He wants to run two of the rats through a maze,one rat at a time.How many subsets of 2 rats could he choose to run through the maze if order does matter?

A)6
B)10
C)20
D)120

Question 60

A sample of 500 people aged 30 - 40 years old were interviewed to study the relationship between whether a person graduated from college or only high school and whether s/he changed jobs in the last 5 years.The results are found in the contingency table below.
Answers below have been rounded to two decimal places.
What is the probability that an individual has changed jobs,given that they have graduated from high school only?

A).23
B).35
C).48
D).65

Question 61

A marketing researcher at a computer company did a study examining user satisfaction with two operating systems.A total of 300 users were surveyed on the type of operating system used and their satisfaction with it.Use the following data set to answer questions 6-14:
Given that it is impossible for a user to be satisfied and not satisfied with system 10 at the same time,these two events are called ___________________________.

A)simple events
B)conditional probabilities
C)complex probabilities
D)mutually exclusive events

Question 62

Which of the following is NOT one of the three conceptualizations of probability discussed in the text?

A)classical probability theory
B)standard scores derived from probabilities
C)estimation of probabilities from data
D)events occurring in the long run

Question 63

A marketing researcher at a computer company did a study examining user satisfaction with two operating systems.A total of 300 users were surveyed on the type of operating system used and their satisfaction with it.Use the following data set to answer questions 6-14:
Using sampling with replacement,what is the probability of randomly selecting someone who is satisfied with system 10,and then randomly selecting someone who is satisfied with system 9?

A).096
B).573
C).167
D).799

Question 64

A marketing researcher at a computer company did a study examining user satisfaction with two operating systems.A total of 300 users were surveyed on the type of operating system used and their satisfaction with it.Use the following data set to answer questions 6-14:
What is the probability that a user is satisfied with either system 9 or system 10?

A).813
B).187
C).740
D).260

Question 65

A new drug developed to fight depression has a .20 probability of causing dizziness.A person takes the drug 100 times.
What is the probability of the person getting dizzy 10 times or fewer?

A).0062
B).0124
C).2643
D).5286

Question 66

A marketing researcher at a computer company did a study examining user satisfaction with two operating systems.A total of 300 users were surveyed on the type of operating system used and their satisfaction with it.Use the following data set to answer questions 6-14:
What is the probability that a person is satisfied given that they use system 10?

A).295
B).893
C).705
D).107

Question 67

Probability theory is important to understand because

A)understanding basic probability theory helps in understanding many statistical tests.
B)probability is the foundation of inferential statistics used in psychology.
C)probability is the foundation of many descriptive statistical techniques used in psychology.
D)all of these

Question 68

A marketing researcher at a computer company did a study examining user satisfaction with two operating systems.A total of 300 users were surveyed on the type of operating system used and their satisfaction with it.Use the following data set to answer questions 6-14:
What is the probability that a person is satisfied given that they use system 9?

A).295
B).893
C).705
D).107

Question 69

According to classical probability theory,the act of selecting a card at random from a deck is called a(n)

A)trial
B)event
C)conditional probability
D)joint probability

Question 70

A biopsychologist is interested in how quickly rats learn a complicated maze.He puts 5 rats,labeled A,B,C,D,and E,in a box.He wants to run two of the rats through a maze,one rat at a time.What is the probability that the biopsychologist will run rat B through the maze first and then run rat E through the maze second?

A).0083
B).05
C).10
D).40

Question 71

A biopsychologist is interested in how quickly rats learn a complicated maze.He puts 5 rats,labeled A,B,C,D,and E,in a box.He wants to run two of the rats through a maze,one rat at a time.How many subsets of 2 rats could he choose to run through the maze if order does NOT matter?

A)10
B)15
C)20
D)40

Question 72

The probability of drawing a red card from a deck of normal playing cards is .5 (half red,half black).A magician draws 12 cards from the deck.What is the probability that the magician draws 10 red cards?

A).0002
B).004
C).016
D).064

Question 73

Assume a researcher has grouped people into categories by age,as follows: 20-29,30-39,40-49,50-59.A person can only be placed into one of these categories,thus these categories are said to be

A)exhaustive
B)permutations
C)joint probabilities
D)mutually exclusive

Question 74

The probability of drawing a red card from a deck of normal playing cards is .5 (half red,half black).A magician draws 12 cards from the deck.What is the probability that the magician draws 8 red cards?

A).0002
B).042
C).121
D).696

Question 75

A marketing researcher at a computer company did a study examining user satisfaction with two operating systems.A total of 300 users were surveyed on the type of operating system used and their satisfaction with it.Use the following data set to answer questions 6-14:
What is the probability that a person uses system 10?

A).813
B).187
C).740
D).260

Question 76

What type of data table is useful for calculating probabilities?

A)frequency distribution
B)means table
C)contingency table
D)marginal means table

Question 77

A new drug developed to fight depression has a .20 probability of causing dizziness.A person takes the drug 100 times.
What is the mean and standard deviation of the binomial distribution of this data?

A)mean = 20,standard deviation = 4
B)mean = 20,standard deviation = 16
C)mean = 80,standard deviation = 4
D)mean = 80,standard deviation = 16

Question 78

If the observations are so different from the expected result of a study that the difference cannot be due to chance,then you should reject the _____.

A)alpha level
B)conditional probability
C)alternative hypothesis
D)null hypothesis

Question 79

A marketing researcher at a computer company did a study examining user satisfaction with two operating systems.A total of 300 users were surveyed on the type of operating system used and their satisfaction with it.Use the following data set to answer questions 6-14:
What is the probability that a person uses system 9?

A).813
B).187
C).740
D).260

Question 80

A marketing researcher at a computer company did a study examining user satisfaction with two operating systems.A total of 300 users were surveyed on the type of operating system used and their satisfaction with it.Use the following data set to answer questions 6-14:
Which of the following is an expression of the probability of a simple event?

A)The probability that a user is satisfied given use of either system 9 or 10.
B)The probability that a user is not satisfied with system 9.
C)The probability that a user is not satisfied with either system 9 or 10.
D)The probability that people use system 9,but not system 10.