CHAPTER 1

Which of the variables is not considered to be numerical?
A.
The type of operating system
B.
Answer The year purchased
C.
the number of Brian's classmates
D.
The amount of memory
Question What is the difference between a census and a sample survey?
A.
A census attempts to include the entire population in the survey whereas a sample
survey only studies some of the members of the population.
B.
Answer
A census looks at a larger group than a sample survey to gather information about the
population.
C.
A census can study many variables whereas a sample survey can only study one or
two.
D.
A census can only be conducted by a government whereas a sample survey can be
conducted by anyone.
Consider the three situations:
I. You ask a sample of doctors about the health risks involved with going out in the
cold without a jacket.
II. On cold days, you record which of your classmates come to school without a
jacket. Later, you record how many of those students become sick. You take notes
and observe at a local gym your fellow members who go outside with a wet head and
Question
notice if they are sick when they return to the gym at a later date.
III. You find 30 adults and divide them into two groups. The first group is told not to
wear jackets on cold days, the other group is told to wear jackets on cold days.You
then compare the number from each group who get sick after a string of cold days.
Which of the following situations is an example of an observational study?
A.
Situation II
Answer B.
Situation I
C.
Situation III
Consider the three situations:
I. You ask a sample of doctors about the health risks involved with going out in the
cold without a jacket.
II. On cold days, you record which of your classmates come to school without a
jacket. Later, you record how many of those students become sick. You take notes
and observe at a local gym your fellow members who go outside with a wet head and
Question notice if they are sick when they return to the gym at a later date.
III. You find 30 adults and divide them into two groups. The first group is told not to
wear jackets on cold days, the other group is told to wear jackets on cold days.You
then compare the number from each group who get sick after a string of cold days.
Which of the following situations is an example of an experiment?
Answer
A.
Situation III
B.
Situation I
C.
Situation II
Question The Nielsen television ratings is an example of a:
A.
Experiment
B.
Population
Answer C.
Census
D.
Sample Survey
Question The difference between an experiment and an observational study is:
A.
An observational study tries to gather information without interfering; an experiment
looks to actively impose a treatment to see how they respond.
Answer
B.
An experiment tries not to change behavior, an observational study does.
C.
An experiment deliberately imposes a treatment whereas an observational study
measures the unintentional effects of the treatment as a result of the observation being
done.
Brian gathers data from his classmates about the computers they own:
Question
What are the individuals in this data set?
A.
The year purchased
B.
Answer Brian's classmates
C.
The amount of memory
D.
The type of operating system
A local newspaper in the State of Connecticut conducts a poll on whether the people
Question of the state believe the "No Child Left Behind" law is effective. The newspaper
contacts 1000 subscribers. The population of this poll is:
A.
Those who favor or disapprove of the "No Child Left Behind" law
B.
Answer People who live in the State of Connecticut
C.
Those who are affected by "No Child Left Behind"
D.
The 1000 people surveyed
Question The Gallup Poll is an example of a:
A.
Answer
Population
B.
Census
C.
Experiment
D.
Sample Survey
CHAPTER 2

The BusinessWeek online poll is available at the BusinessWeek website.
Visitors can simply click appropriate buttons to vote. In response to the
Question question "Do you think Google is too powerful?" (March 27, 2007), 1336 said
"Yes," 2051 said "No", and 335 said that they were not sure.
Why do you think the poll may give unreliable information?
A.
Business Week uses convenience sampling.
Answer B.
Online polls may not be reliable.
C.
Sample size is small.
As part of a project for a political science class, a student decided to conduct
an online poll. The student asked the following question: “Do you think that
Question illegal immigrants should be allowed to pay instate tuition, even though they
are not legal citizens of that state?” Possible responses were Yes, No, and
Unsure. Of those who responded, 81% said No, 19% said Yes, and 0% said
Unsure.
Which of the following statements correctly explains the result of the poll
with respect to reliability and bias?
A.
The result of the poll is biased because it is based on voluntary response
method.
Answer B.
The result of the poll is not reliable because it is based on convenience sample
method.
C.
The result of the poll can be considered reliable and unbiased.
Highway planners decided to make a main street in West Lafayette, Indiana, a
one-way street. The Lafayette Journal and Courier took a one-day poll by
inviting readers to call a telephone number to record their comments. The next
day, the paper reported: “Journal and Courier readers overwhelmingly prefer
two-way traffic flow in West Lafayette’s Village area to one-way streets. By
nearly a 7-1 margin, callers to the newspaper’s Express Yourself opinion line
Question
on Wednesday complained about the one-way streets that have been in place
since May. Of the 98 comments received, all but 14 said no to one-way.”
What population do you think the newspaper wants information about?
A.
Highway planners
Answer
B.
Residents of West Lafayette (and Lafayette)
C.
All readers of Lafayette Journal and Courier
Question
A national survey of TV network news viewers found that 48% said they
would believe a phone-in poll of 300,000 persons rather than a random sample
of 1000 persons. Of the viewers, 42% said they would believe the random
sample poll.
Which of the following statements correctly explains why the opinions of only
1000 randomly chosen respondents are a better guide to what all people think
than the opinions of 300,000 callers?
A.
The 1000 randomly chosen respondents represent the population as a whole,
whereas the 300,000 callers did not do so.
B.
Answer
The 1000 randomly chosen individuals were chosen as a personal choice of
the TV network, whereas the 300,000 called voluntarily and do not represent
the choice of the TV network.
C.
The 1000 randomly chosen respondents represent the intellectual population,
whereas the 300,000 callers did not do so
A university has 30,000 undergraduate and 10,000 graduate students. A
survey of student opinion concerning health care benefits for domestic
partners of students selects 300 of the 30,000 undergraduate students at
random and then separately selects 100 of the 10,000 graduate students at
Question
random. The 400 students chosen make up the sample.
Which of the following statements correctly explains why this sampling
method gives each student an equal chance to be chosen?
Every undergraduate student has a 75% chance of being selected and every
graduate student has a 25% chance of being selected, which is proportional to
Answer
the makeup of the student body.
Any student has a 50% chance of being chosen, since the student is either
selected or not.
Any student, undergraduate or graduate, has a 1 in 100 chance of being
selected.
The BusinessWeek online poll is available at the BusinessWeek
website. Visitors can simply click appropriate buttons to vote. In response to
the question "Do you think Google is too powerful?" (March 27, 2007), 1336
said "Yes," 2051 said "No", and 335 said that they were not sure.
Question
Above the poll question, the following statement was mentioned: “Google’s
accelerating lead in search and its moves into software and traditional
advertising are sparking a backlash among rivals.” How might this statement
affect the polls?
A.
The statement would have increased the sample size.
Answer B.
The statement would have made the poll biased.
C.
The statement would have made the poll reliable.
Question
A college wants to gather student opinion about parking for students on
campus. It isn’t practical to contact all students.
Which of the following is an example of a good way to choose a sample?
Answer
A.
Selection of random 50 students and interviewing them
B.
A survey form published in the campus newspaper
C.
Interviewing students when they leave the parking at the campus
In 2005 the San Francisco Bay Times reported on a poll in New Zealand that
found that New Zealanders opposed the nation’s new gay-inclusive civilunions law by a 3-1 ratio. This poll was a call-in poll that cost $1 to participate
in. The San Francisco Bay Times article also reported that a scientific polling
Question
organization found that New Zealanders favor the law by a margin of 56.4%
to 39.3%.
Which of the following statements is correct about the reliability of the polls?
A.
The polling result of neither call-in poll nor the scientific polling organization
can be considered reliable as there is so much difference in the results of two
polls.
B.
Answer
The scientific polling organization may not have produced the reliable result
and therefore causing its results to differ so much with the result of the call-in
poll.
C.
The call-in poll used the Voluntary Response method, so their poll results
cannot be considered reliable.
To assess how its teaching assistants are performing, the statistics department
at a large university randomly selects three of its teaching assistants each week
Questio and sends a faculty member to visit their classes. The current list of 20
teaching assistants is given below.
n
01. Bautista 06. Frazier 11. Miller 16. Walters
02. Bolen 07. Kumar 12. Podboy 17. Wang
03. Clottey 08. Lam
13. Roy
18. Weimer
04. Counts 09. Lovesky 14. Schumacher 19. Yu
05. Draper 10. Marin 15. Tower 20. Zhang
The department examines the first 13 two-digit groups in line 116 of Table A.
Line 116 is:
14459
26056
31424
80371
65103
62253
50490
61181.
The first 13 two-digits groups are: 14, 45, 92, 60, 56, 31, 42, 48, 03, 71, 65, 10,
and 36.
Which of the following teaching assistants would the sample consist of?
A.
Clottey, Marin, and Schumacher
B.
Answer Draper, Marin, and Schumacher
C.
Bautista, Counts, and Draper
D.
Schumacher, Counts, and Draper
Choosing at random is a "fair" way to decide who gets some scarce good, in
the sense that everyone has the same chance to win. However, random choice
isn’t always a good idea. At times we don’t want to treat everyone at the same
Question
because some people have a better claim.
In which of the following situations, would you not prefer to choose at
random?
A.
Answer
The basketball arena has 4000 student seats, and 7000 students want tickets.
B.
Young men chosen for army service, during the Vietnam War.
C.
The list of people waiting for liver transplants is larger than the number of
livers available.
Highway planners decided to make a main street in West Lafayette, Indiana, a
one-way street. The Lafayette Journal and Courier took a one-day poll by
inviting readers to call a telephone number to record their comments. The next
day, the paper reported: “Journal and Courier readers overwhelmingly prefer
two-way traffic flow in West Lafayette’s Village area to one-way streets. By
Question nearly a 7-1 margin, callers to the newspaper’s Express Yourself opinion line
on Wednesday complained about the one-way streets that have been in place
since May. Of the 98 comments received, all but 14 said no to one-way.”
Which of the following statements is appropriate about the proportion of the
population who favor one-way streets?
A.
The proportion of the population who favor one-way streets is probably equal
to the proportion 14/98 in the sample.
Answer
B.
The proportion of the population who favor one-way streets is probably larger
than the proportion 14/98 in the sample.
C.
The proportion of the population who favor one-way streets is probably
smaller than the proportion 14/98 in the sample.
Question
The BusinessWeek online poll is available at the BusinessWeek
website. Visitors can simply click appropriate buttons to vote. In response to
the question "Do you think Google is too powerful?" (March 27, 2007), 1336
said "Yes," 2051 said "No", and 335 said that they were not sure.
What was the sample size for this poll?
A.
335
B.
Answer 3722
C.
3136
D.
2051
CHAPTER 3

A November 2007 Gallup Poll of 1004 adults found that 572 are satisfied with
the total cost they pay for their health care. The announced margin of error is
Question
±3 percentage points. The announced confidence level is 95%. Which of the
statements is a correct and complete confidence statement in this scenario?
A.
We are 95% confident that p is between 54% and 60%.
Answer B.
We are 95% confident that p is 57%.
C.
We are sure that p is between 54% and 60%.
A management student is planning a project on student attitudes toward parttime work while attending college. She develops a questionnaire and plans to
ask 25 randomly selected students to fill it out. Her faculty adviser approves
the questionnaire but suggests that the sample size should be increased to at
Question
least 100 students.
Which of the following statements correctly explains the advantage of the
larger sample?
A.
A larger sample size will give less biased results.
B.
Answer A larger sample size will give low bias and low variability.
C.
A larger sample size will give less variable results.
A November 2007 Gallup Poll of 1004 adults found that 572 are satisfied with
the total cost they pay for their health care. The announced margin of error is
Question
±3 percentage points. The announced confidence level is 95%. Which
statement is true?
A.
The population parameter p is the proportion of the sample that is satisfied
with the total cost they pay for their health care.
B.
Answer
The population parameter p is the proportion, of the total number of samples,
which is within the limits of margin of error.
C.
The population parameter p is proportion of the population who is satisfied
with the total cost they pay for their health care.
A New York Times Poll on women’s issues interviewed 1025 women
randomly selected from the United States, excluding Alaska and Hawaii. The
poll found that 47% of the women said they do not get enough time for
themselves. The poll announced a margin of error of ±3 percentage points for
Question
95% confidence in its conclusions.
Which of the following statements is the correct confidence statement, in
relation to the scenario?
A.
We are 95% confident that between 44% and 50% of all women would say
that they do not get enough time for themselves.
Answer
B.
We are sure that between 44% and 50% of all women would say that they do
not get enough time for themselves.
C.
We are 95% confident that 47% of all women would say that they do not get
enough time for themselves.
A management student is planning a project on student attitudes toward parttime work while attending college. She develops a questionnaire and plans to
ask 25 randomly selected students to fill it out. Her faculty adviser approves
the questionnaire but suggests that the sample size should be increased to at
Question
least 100 students.
Which of the following statements correctly identifies the relation between the
margin of error for sample sizes of 100 and 25?
A.
The margin of error for a sample size of 100 will be approximately one-fourth
Answer of the margin of error for a sample size of 25.
B.
The margin of error for a sample size of 100 will be approximately double of
the margin of error for a sample size of 25.
C.
The margin of error for a sample size of 100 will be approximately half of the
margin of error for a sample size of 25.
In October 2007, the Gallup Poll asked a sample of 1010 adults, “Are you in
favor of the death penalty for a person convicted of murder?” The proportion
who said they were in favor was 69%. Gallup says that the margin of error for
Question this poll is ±3 percentage points.
Suppose you want a margin of error half as large as estimated by Gallup. How
many people must you plan to interview?
A.
4040
Answer B.
505
C.
2020
A New York Times Poll on women’s issues interviewed 1025 women
randomly selected from the United States, excluding Alaska and Hawaii. The
poll found that 47% of the women said they do not get enough time for
themselves. The poll announced a margin of error of ±3 percentage points for
95% confidence in its conclusions.The confidence statement, in relation to the
Question
given scenario, is: “We are 95% confident that between 44% and 50% of all
women would say that they do not get enough time for themselves.”
Which of the following statements correctly explains the meaning of the term
‘95% confidence’, in the confidence statement?
A.
The interval 44% to 50% is based on a procedure that produces a margin of
error (of ±3) 95% of the time.
B.
Answer
The interval 44% to 50% is based on a procedure that includes a sample
representing 95% of population.
C.
The interval 44% to 50% is based on a procedure that captures the true
population value 95% of the time.
In October 2007, the Gallup Poll asked a sample of 1010 adults, “Are you in
favor of the death penalty for a person convicted of murder?” The proportion
who said they were in favor was 69%.Gallup says that the margin of error for
Question this poll is ±3 percentage points.
Which of the following statements correctly explains the phrase “margin of
error plus or minus 3 percentage points?”
A.
The true value is within 3 percentage points of the result obtained in this poll.
B.
Answer
The results are based on a method that is 95% of the time within 3 percentage
points of the true value.
C.
The result of the poll is different from the true value by more than 3
percentage points.
In February 2004, USA Today conducted an online poll. Visitors to their Web
site were asked the following question: “Should the U.S. pass a constitutional
amendment banning gay marriage?” Visitors could vote by clicking a button.
The result as of 3:30 pm on February 25 was that 68.61% voted “No” and
Question 31.39% voted “Yes.” A total of 63,046 votes had been recorded. It was found
that the margin of error for 95% confidence for a sample of this size is roughly
equal to four-tenths of one percentage point.
Which of the following statements correctly explains the result of the poll?
A.
The margin of error is 0.4%. Therefore, it can be said with 95% confidence
that 68.61%, plus or minus 0.4%, of American adults are opposed to having
the United States pass a constitutional amendment banning gay marriage.
B.
68.61% is the correct value of population parameter p, representing the
proportion of American adults who are opposed to have the United States pass
Answer
a constitutional amendment banning gay marriage.
C.
The result of the poll is based on a voluntary response sample. Therefore, it
cannot be said that 68.61%, plus or minus 0.4%, of American adults are
opposed to having the United States pass a constitutional amendment banning
gay marriage.
A New York Times Poll on women’s issues interviewed 1025 women
randomly selected from the United States, excluding Alaska and Hawaii. The
poll also interviewed 472 randomly selected men. In conclusions about
women, the poll announced a margin of error of ±3 percentage points for 95%
Question
confidence.
Which of the following statements is correct about the relation of margin of
error for women and margin for error for men?
A.
Answer The margin of error for men will be equal to the margin of error for women.
B.
The margin of error for men will be greater than margin of error for women.
C.
The margin of error for men will be smaller than the margin of error for
women.
A New York Times Poll on women’s issues interviewed 1025 women
randomly selected from the United States, excluding Alaska and Hawaii. The
poll found that 47% of the women said they do not get enough time for
themselves. The poll announced a margin of error of ±3 percentage points for
Question
95% confidence in its conclusions.
Which of the following statements correctly explains why we can’t just say
that 47% of all adult women do not get enough time for themselves?
A.
The result, that 47% women said they do not get enough time for themselves,
is based on a sample that does not contain an equal proportion of the
population from each state.
B.
Answer
The result, that 47% women said they do not get enough time for themselves,
is based on a small sample size.
C.
The 47% of women who said they do not get enough time for themselves
represents the proportion of the sample and not the proportion of the
population.
CHAPTER 4

A survey of users of the Internet in 1995, when Internet use was much less
Question common than now, found that males outnumbered females by nearly 2 to 1.
This was a surprise because earlier surveys had put the ratio of men to women
closer to 9 to 1. Later in the article we find this information: "Detailed surveys
were sent to more than 13,000 organizations on the Internet; 1,468 usable
responses were received. According to Mr. Quarterman, the margin of error is
2.8 percent, with a confidence level of 95 percent."
Which of the following do you think is the source of error that has been
disregarded?
A.
Nonresponse
Answer B.
Voluntary response
C.
Undercoverage
You want to investigate the attitudes of students at your school toward the
school’s policy on extra fees for lab courses. You have a grant that will pay
Question the costs of contacting about 500 students.
Which statement is true?
A.
A stratified sample can be created by using student majors as strata.
Answer
B.
A cluster sample is impossible in this situation.
C.
A cluster sample could be obtained by selecting ten students at random from
EACH major.
The following question was asked in a sample survey: "In light of
skyrocketing gasoline prices, we should consider opening up a very small
Question amount of Alaskan wilderness for oil exploration as a way of reducing our
dependence on foreign oil. Do you agree or disagree?"
A.
The question is slanted toward a desired response against the statement.
B.
Answer The question is not slanted toward a desired response.
C.
The question is slanted toward a desired response in favor of the statement.
You want to investigate the attitudes of students at your school toward the
school’s policy on extra fees for lab courses. You have a grant that will pay
the costs of contacting about 500 students.
Question
Assuming that budget is not a constraint, which of the following would be the
most appropriate method of contacting the students?
A.
Mailed questionnaires
B.
Answer Telephone interviews
C.
Face-to-face interviews
In a sample survey, the following question was asked: "Which of the
following best represents your opinion on gun control?
1. The government should take away our guns.
Question
2. We have the right to keep and bear arms.
Identify the correct statement with reference to the survey question asked:
A.
The question is slanted toward a desired response in favor of the second
statement.
Answer B.
The question is slanted toward a desired response in favor of the first
statement.
C.
The question is not slanted toward a desired response.
When the Current Population Survey asked the adults in its sample of 50,000
households if they voted in the 2000 presidential election, 55% said they had.
The margin of error was less than 1%. But, as a matter of fact, only 51% of
Question the adult population voted in that election.
Why do you think the CPS result missed by much more than the margin of
error?
A.
The margin of error accounts for random sampling error only.
Answer B.
The margin for error is not a suitable measure of sampling error.
C.
The margin of error is incorrectly calculated.
According to a March 2007 USA Today/Gallup Poll, 43% of Americans
identify themselves as baseball fans. That is low by recent standards, as an
average of 49% of Americans have said they were fans of the sport since
Gallup started tracking this measure in 1993. The high point came in 1998,
when Sammy Sosa and Mark McGwire pursued (and ultimately surpassed)
Roger Maris’s single-season home run record, at which time 56% of
Americans considered themselves baseball fans. The Gallup press release
Question
says: "For results based on this sample, one can say with 95% confidence that
the maximum error attributable to sampling and other random effects is ±3
percentage points."
Which of the following sources of error do you think has been included in this
reported margin of error?
A.
Voluntary response
B.
Undercoverage
Answer C.
Nonresponse
D.
Random sampling error
The following example illustrates the idea of a systematic sample. Suppose
that we must choose 4 rooms out of the 100 rooms in a dormitory. Because
100/4 = 25, we can think of the list of 100 rooms as four lists of 25 rooms
each. Choose 1 of the first 25 rooms at random, using Table A. The sample
Question will contain this room and the rooms 25, 50, and 75 places down the list from
it. If 13 is chosen, for example, then the systematic random sample consists of
the rooms numbered 13, 38, 63, and 88. Use Table A to choose a systematic
random sample of 5 rooms from a list of 200.
True or False:
Like an Simple Random Sample (SRS), a systematic sample gives all
individuals the same chance to be chosen.
A systematic sample is, however, not an SRS.
True
False
Answer
Question Match the following sources of errors with appropriate categories.
Match Question Items
A. - A.
The subject lies about past drug use.
Answer Items
A.
B. - B.
Nonsampling error: a
response error
B.
A typing error is made in recording the
data.
C. - C.
Nonsampling error: a
processing error
C.
Answer
Data are gathered by asking people to go Sampling error: a
to a Web site and answer questions online. voluntary response sample
CHAPTER 5

What is the preferred treatment for breast cancer that is detected in its early
stages? The most common treatment was once removal of the breast. It is now
usual to remove only the tumor and nearby lymph nodes, followed by
radiation. To study whether these treatments differ in their effectiveness, a
Question
medical team examines the records of 25 large hospitals and compares the
survival times after surgery of all women who have had either treatment.
Identify the explanatory and response variables in this study.
Answer
A.
Explanatory variable: Treatment method; Response variable: Survival times
B.
Explanatory variable: Removal or non-removal of breast; Response variable:
Women with breast cancer
C.
Explanatory variable: Survival times; Response variable: Treatment method
D.
Explanatory variable: Women with breast cancer: Response variable:
Removal or non-removal of breast
Question
What is the preferred treatment for breast cancer that is detected in its early
stages? The most common treatment was once removal of the breast. It is now
usual to remove only the tumor and nearby lymph nodes, followed by
radiation. To study whether these treatments differ in their effectiveness, a
medical team examines the records of 25 large hospitals and compares the
survival times after surgery of all women who have had either treatment.
True or false:
The study is not an experiment because no treatment is actively imposed, and
the patients or their doctors selected the treatment to be used.
Answer
True
False
Can aspirin help prevent heart attacks? The Physicians’ Health Study, a large
medical experiment involving 22,000 male physicians, attempted to answer
this question. One group of about 11,000 physicians took an aspirin every
second day, while the rest took a placebo. After several years, the study found
Question that subjects in the aspirin group had significantly fewer heart attacks than
subjects in the placebo group.
Match the terms used in experiments with their corresponding values in view
of the given study.
Answer
Match Question Items Answer Items
A. - A.
A.
Medication
B. - B.
Explanatory variable
B.
Health
C. - C.
Response variable
C.
Physicians
Subject
A manufacturer of chisels is interested in determining how the angle at which
the cutting edge is sharpened affects tool abrasion. To answer this question,
engineers obtain 20 similar chisels. They sharpen five chisels at each of 22.5,
25, 27.5, and 30 degrees. Then, they measure the amount of abrasion (rated on
Question
a scale of 1 to 10, with 10 being the worst) after cutting several mortises
(square holes) in 3/4-inch hard maple boards.
Which of the following is the explanatory variable in the given study?
A.
Tool abrasion
B.
Mortises
Answer C.
Sharpening of chisels
D.
Angle of cutting edge
A large study used records from Canada’s national health care system to
compare the effectiveness of two ways to treat prostate disease. The two
Question treatments are traditional surgery and a new method that does not require
surgery. The records described many patients whose doctors had chosen one
or the other method. The study found that patients treated by the new method
were significantly more likely to die within eight years.
You have 300 prostate patients who are willing to serve as subjects in an
experiment to compare the two methods.
Which of the following statements describes an appropriate design for this
randomized comparative experiment?
A.
Assign the nonsurgical treatment to all patients and observe recovery. Then,
assign the surgical treatment to the patients who do not recover and again
observe recovery.
B.
Ask the patients to select the treatment method they want and divide them into
two groups, one group with patients going for surgical treatment and the other
Answer
group for nonsurgical treatment. Compare the recovery of patients in each
group.
C.
Make two groups of 150 patients each by using random assignment. Give the
surgical treatment to one group and the nonsurgical treatment to the other
group. Observe the recovery of patients in each group.
Some medical researchers suspect that the drug memantine improves the
cognition of patients with moderate to severe Alzheimer’s disease. You have
available 50 people with moderate to severe Alzheimer’s disease who are
willing to serve as subjects.
Consider the following design for the experiment, taking the placebo effect
Question into account, will be to assign the placebo treatment to all 50 people. Next,
measure the cognition of these people. Then, assign the memantine treatment
to all and again check cognition.
True or false:
The given design is the most appropriate design for the experiment.
Answer
True
False
Does regular exercise reduce bone loss in postmenopausal women? Here are
two ways to study this question.
• A researcher finds 1000 postmenopausal women who exercise regularly.
She matches each with a similar postmenopausal woman who does not
exercise regularly, and she follows both groups for 5 years.
Question
• Another researcher finds 2000 postmenopausal women who are willing to
participate in a study. She assigns 1000 of the women to a regular program of
supervised exercise. The other 1000 continue their usual habits. The
researcher follows both groups for 5 years.
Which of the following statements is correct with reference to the two studies?
A.
Only the second study will produce trustworthy data.
B.
Answer Both of the studies will produce trustworthy data.
C.
Only the first study will produce trustworthy data.
D.
Neither of the studies will produce trustworthy data.
A large study used records from Canada’s national health care system to
compare the effectiveness of two ways to treat prostate disease. The two
treatments are traditional surgery and a new method that does not require
surgery. The records described many patients whose doctors had chosen one
or the other method. The study found that patients treated by the new method
were significantly more likely to die within eight years.
Question
Further study of the data showed that this conclusion was wrong. The extra
deaths among patients treated with the new method could be explained by
lurking variables.
Identify a lurking variable that might be confounded with a doctor’s choice of
surgical or nonsurgical treatment.
A.
Choice of the patient’s relatives
B.
Answer Non-availability of surgical instruments
C.
Patient’s chance of survival
Can aspirin help prevent heart attacks? The Physicians’ Health Study, a large
medical experiment involving 22,000 male physicians, attempted to answer
this question. One group of about 11,000 physicians took an aspirin every
second day, while the rest took a placebo. After several years, the study found
Question that subjects in the aspirin group had significantly fewer heart attacks than
subjects in the placebo group.
What is the meaning of the term “significantly” in “significantly fewer heart
attacks”?
A.
It means “definitely occurred by chance if there was no difference between the
aspirin and placebo groups.”
B.
It means “likely to have occurred by chance if there was no difference
between the aspirin and placebo groups.”
Answer
C.
It means “definitely could not have occurred by chance if there was no
difference between the aspirin and placebo groups.”
D.
It means “unlikely to have occurred by chance if there was no difference
between the aspirin and placebo groups.”
A manufacturer of chisels is interested in determining how the angle at which
the cutting edge is sharpened affects tool abrasion. To answer this question,
engineers obtain 20 similar chisels. They sharpen five chisels at each of 22.5,
25, 27.5, and 30 degrees. Then, they measure the amount of abrasion (rated on
Question
a scale of 1 to 10, with 10 being the worst) after cutting several mortises
(square holes) in 3/4-inch hard maple boards.
Identify the response variable in the given study.
A.
Mortises
Answer B.
Amount of abrasion
C.
Cutting edge
A study, mandated by Congress when it passed No Child Left Behind in 2002,
evaluated 15 reading and math software products used by 9424 students in
132 schools across the country during the 2004–2005 school year. It is the
largest study that has compared students who received the technology with
those who did not, as measured by their scores on standardized tests. There
Question
were no statistically significant differences between students who used
software and those who did not.
Which of the following statements correctly describes the meaning of “no
statistically significant differences”?
A.
Answer There was no difference in the scores of students who used software and those
who did not.
B.
There was a large difference in the scores of students who used software and
those who did not. This difference could not have occurred by chance.
C.
There almost certainly was some difference in the scores of students who used
software and those who did not. However, the difference was so small that it
may have been due to chance alone.
The death rates of surgical patients differ for operations in which different
anesthetics are used. An observational study found these death rates for four
anesthetics:
Anesthetic:
Question Death rate:
Halothane
1.7%
Pentothal
1.7%
Cyclopropane
3.4%
Ether
1.9%
This is not good evidence that cyclopropane is more dangerous than the other
anesthetics.
Identify a lurking variable that may be confounded with the choice of
anesthetic in surgery and that could explain the different death rates.
A.
Financial background of the patient
B.
Answer Types of surgical instruments
C.
Physical condition of the patient
CHAPTER 6

Researchers conducted an experiment to compare the effects of a
carbohydrate-restricted diet (low-carb diet) and a calorie- and fat-restricted
diet (low-fat diet) on weight loss. The researchers are concerned that the
effect of diet may depend on gender, so sex is treated as a blocking
Question
variable. There are 122 severely obese individuals available for the study, 52
of whom are men and 70 of whom are women.
Identify the most appropriate experiment design for the experiment.
A.
Randomly assign all subjects to two groups. Next, split each group into two
sub-groups by sex. Next, assign one sub-group to low-carb diet and the other
sub-group to the low-fat diet in both the groups. Compare weight loss within
the groups.
B.
Use a coin to decide which subject receives which treatment. Divide subjects
into two groups depending on which treatment they are receiving. Next, split
Answer
each group into two sub-groups by sex. Compare weight loss within the
groups.
C.
Split the subjects into two groups by sex. Create two sub-groups each in the
two groups by random assignment. Next, within each group, assign one subgroup to low-carb diet and the other sub-group to the low-fat diet. Compare
weight loss within the groups.
The progress of a type of cancer differs in women and men. A clinical
experiment to compare four therapies for this cancer therefore treats sex as a
blocking variable.
Question
500 male and 300 female patients have agreed to act as subjects. Which of the
following approaches will you use to create a block design for the
experiment?
Answer
A.
Observe the current state of cancer. Split the subjects into two groups using
sex as the blocking variable and then randomly assign subjects in each group
into four sub-groups. Assign each sub-group to one of the treatments. Observe
the progress of cancer.
B.
Observe the current state of cancer. Randomly assign subjects to two groups
and using sex as the blocking variable, split each group to two sub-groups.
Assign each sub-group to one of the treatments. Observe the progress of
cancer.
C.
Observe the current state of cancer. Assign the subjects to the four treatments
in one randomization. Observe the progress of cancer for male and female
subjects.
A food scientist wants to study the effect of the type of pan and the amount of
sodium bicarbonate used in preparing peanut brittle on the flavor of the peanut
brittle. In an experiment, peanut brittle is baked in four types of pans: iron,
aluminum, stainless steel, and nonstick stainless steel. Sodium bicarbonate is
used in three different quantities in the recipe: 0, 2, and 4 grams. Ten batches
Question
of peanut brittle are prepared at each combination of pan type and the amount
of sodium bicarbonate. A panel of tasters scores each batch on the intensity of
peanut, sweet, and buttery flavors.
How many batches of peanut brittle are needed for the experiment?
A.
40
Answer B.
120
C.
30
Cars sold in the United States since 1986 have been required to have a high
center brake light in addition to the usual two brake lights at the rear of the
vehicle. This safety requirement was justified by randomized comparative
experiments with fleets of rental and business cars. The experiments showed
that the third brake light reduced rear-end collisions by as much as 50%. After
almost a decade in actual use, the Insurance Institute found only a 5%
reduction in rear-end collisions, helpful but much less than the experiments
predicted. Most cars did not have the extra brake light when the experiments
were carried out, so it caught the eye of following drivers. Now that almost all
Question
cars have the third light, it no longer captures attention.
Canada too now requires that cars be equipped with “daytime running lights,”
headlights that automatically come on at a low level when the car is started.
Some manufacturers are now equipping cars sold in the United States with
running lights.
What cautions do you draw from the US example, which also apply to an
experiment on the effects of running lights in Canada?
A.
In the US, most cars did not have the extra brake light when the experiment
was carried out. If people in Canada are more willing to coordinate, the results
can be in favor of daytime running lights.
B.
Answer
Owing to the difference in topography, the results may be different.
C.
The effect of running lights may be lessened when (if) they become common
enough that people no longer notice them.
An experiment was conducted to determine if the right hand is generally
stronger than the left in right-handed people. Hand strength can be crudely
measured by placing a bathroom scale on a shelf with the end protruding and
then squeezing the scale between the thumb below and the four fingers above.
Question The reading of the scale shows the force exerted.
Identify the randomization for a matched pairs design to compare the strength
of the right and left hands, using 10 right-handed people as subjects.
A.
Create two groups and ask the subjects in each group to use one of the hands
to squeeze the scale. Use a coin to decide which subject in a group will use
which hand.
Answer
B.
Ask each subject to squeeze the scale using both hands, one after the other.
Toss a coin to decide which hand they should use first.
C.
Divide all subjects randomly into two groups and ask subjects in each group to
use either hand.
The National Institutes of Health is at last sponsoring proper clinical trials of
some natural remedies. In one study at Duke University, 330 patients with
mild depression are enrolled in a trial to compare Saint-John’s-wort with a
placebo and with Zoloft, a common prescription drug for depression. The
Question
Beck Depression Inventory is a common instrument that rates the severity of
depression on a 0 to 3 scale.
Identify the completely randomized clinical trial for this study.
A.
Create pairs of similar subjects and randomly assign one of the treatments to
each subject in a group.
B.
Answer
Create groups of subjects in increasing order of the severity of depression and
assign subjects randomly to each treatment within each group.
C.
Randomly divide subjects into three groups, each consisting of 110 subjects.
Assign each group to one of the treatments. Observe change in Beck Inventory
score.
Nurse practitioners are nurses with advanced qualifications who often act
much like primary care physicians. An experiment, which was aimed at
comparing the patients' satisfaction with doctors and nurse practitioners,
assigned 1316 patients who had no regular source of medical care to either a
doctor or a nurse practitioner. All patients had been diagnosed with asthma,
Question diabetes, or high blood pressure before the experiment started. Measures of
the patients’ health and of their satisfaction with their medical care were
recorded after 6 months.
Match the determinants of the experiment with the terms used to describe
them.
Match Question Items
A. - A.
Diagnosis
B. - B.
Answer
Type of Care
C. - C.
Measures of the patients’ health and of their
satisfaction with their medical care
Answer Items
A.
Block variable
B.
Treatment
variable
C.
Response
variable
Studies have suggested that compounds in broccoli might combat the effects
of overexposure to ultraviolet radiation. We conduct an experiment to
determine whether a cream consisting of a broccoli extract reduces sunburn
Question pain. Sixty patients suffering from pain from severe sunburn are
available. What is a good way to conduct the experiment?
A.
Answer Give the cream to all 60 patients, and record their responses.
B.
Divide the patients randomly into three groups of 20 patients each. Give one
group the cream, another group an over-the-counter sunburn relief product,
and the last group a placebo. Record the responses.
C.
Give some patients the cream and others the placebo, being sure to inform the
patients which treatment they are receiving. Record the responses.
CHAPTER 7
Question
The presidential election campaign is in full swing, and the candidates have
hired polling organizations to take regular polls to find out what the voters
think about the issues.
What does the standard of informed consent require the polling organizations
to tell potential respondents?
A.
The kind of questions they will be asked and the approximate amount of time
required to complete the survey
Answer
B.
The election process and date of election
C.
The achievements of the candidate or the political party
Some people think that the law should require that all political poll results be
made public. Otherwise, the possessors of poll results can use the information
to their own advantage. They can act on the information, release only selected
Question parts of it, or time the release for best effect. A candidate’s organization replies
that they are paying for the poll in order to gain information for their own use,
not to amuse the public.
Which of the following statements do you think is appropriate in reference to
the scenario?
A.
The polling organizations can modify the information to their benefit and then
make it public.
B.
Answer
The polling organizations can provide incomplete information, if they do not
want to reveal complete information.
C.
The polling organizations should provide true information if they wish to make
it public.
One of the most important nongovernment surveys in the United States is the
General Social Survey. The GSS regularly monitors public opinion on a wide
Question variety of political and social issues. Interviews are conducted in person in the
subject’s home.
A subject’s responses to GSS questions are:
A.
Confidential
Answer B.
Both confidential and anonymous
C.
Anonymous
Question
In which of the circumstances below would you allow collecting personal
information without the subjects’ consent?
A.
A social psychologist pretends to be converted to membership in a religious
group and attends private meetings to study the behavior patterns of members.
B.
A social psychologist attends public meetings of a religious group to study the
Answer behavior patterns of members.
C.
A government agency takes a random sample of income tax returns to obtain
information on the average income of people in different occupations. Only the
incomes and occupations are recorded from the returns, not the names.
Your college or university has an institutional review board that screens all
studies that use human subjects. Which of the following should be the duties of
Question
the board? (Note: To receive full credit, you may have to select more than one
of the following choices.)
A.
Protect the rights and welfare of human subjects recruited to participate in
research activities.
B.
Decide whether a proposed study is statistically sound.
Answer
C.
Put more proposals in the minimal-risk category to speed the work in the event
of work overload.
D.
Decide whether a proposed study will produce valuable information.
E.
Review the consent forms to ensure that subjects are informed about the nature
of the study and potential risks.
The 2000 census form asked 53 detailed questions, such as: “Do you have
complete plumbing facilities in this house, apartment, or mobile home; hot and
cold piped water, a flush toilet, and bathtub or shower?” The form also asked
the questions about income (in dollars, broken down by source) and about
whether any "physical, mental, or emotional condition causes difficulty in
Question learning, remembering, or concentrating." Some members of Congress
objected to these questions, even though Congress had approved them.
Which of the following statements, do you think, can be a valid reason of the
objection raised by some members of the Congress, against some of the
questions in the form?
A.
Some of the questions in the form were not in the interest of the Congress.
B.
Answer Some of the questions in the form were not valid.
C.
Some of the questions in the form seem to invade privacy of the people.
A government agency takes a random sample of income tax returns to obtain
information on the average income of people in different occupations. Only the
Question incomes and occupations are recorded from the returns, not the names.
True or false: The method used here to collect information is unethical.
Answer
True
False
Long ago, doctors drew a blood specimen from you as part of treating minor
anemia. Unknown to you, the sample was stored. Now researchers plan to use
stored samples from you and many other people to look for genetic factors that
may influence anemia. It is no longer possible to ask your consent because you
are no longer alive. Modern technology can read your entire genetic makeup
from the blood sample.
Perhaps we should use biological materials such as blood samples only from
Question
patients who have agreed to allow the material to be stored for later use in
research. It isn’t possible to say in advance what kind of research, so this falls
short of the usual standard for informed consent.
True or false: This practice is nonetheless acceptable, given complete
confidentiality and the fact that using the sample can’t physically harm the
patient.
Answer
True
False