Multiple Choice Identify the
choice that best completes the statement or answers the question.
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1.
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Can pleasant aromas help a student learn better?
Two researchers believed that the presence of a floral scent could improve a person's learning
ability in certain situations. They had 22 people work through a pencil-and-paper maze six times,
three times while wearing a floral-scented mask and three times wearing an unscented mask. The three
trials for each mask closely followed one another. Testers measured the length of time it took
subjects to complete each of the six trials. They reported that, on average, subjects wearing the
floral-scented mask completed the maze more quickly than those wearing the unscented mask, although
the difference was not statistically significant. This study is
a. | a convenience sample. | b. | an observational study, not an experiment. | c. | an experiment, but not a double-blind experiment. | d. | a double-blind experiment. | e. | a voluntary response sample. |
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2.
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A television station is interested in predicting
whether voters in its viewing area are in favor of federal funding for abortions. It asks its viewers
to phone in and indicate whether they support/are in favor of or are opposed to this. Of the 2241
viewers who phoned in, 1574 (70.24%) were opposed to federal funding for abortions.
Referring
to the information above, the viewers who phoned in are
a. | a voluntary response sample. | b. | a convenience sample. | c. | a probability
sample. | d. | a population. | e. | a
census |
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3.
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A marketing research firm wishes to determine if
the adult men in Laramie, Wyoming, would be interested in a new upscale men's clothing store.
From a list of all residential addresses in Laramie, the firm selects a simple random sample of 100
and mails a brief questionnaire to each. The population of interest is
a. | all adult men in Laramie,
Wyoming. | b. | all residential addresses in Laramie,
Wyoming. | c. | the members of the marketing firm that actually
conducted the survey. | d. | the 100 addresses
to which the survey was mailed. | e. | upscale men’s clothing
stores |
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4.
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In order to assess the opinion of students at the
University of Minnesota on campus snow removal, a reporter for the student newspaper interviews the
first 12 students he meets who are willing to express their opinion. In this case, the sample
is
a. | all those students favoring prompt snow
removal. | b. | all students at universities receiving substantial
snow. | c. | the 12 students interviewed. | d. | all students at the University of Minnesota. | e. | reporters at the
student newspaper |
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5.
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A researcher is interested in the cholesterol
levels of adults in the city in which she lives. A free cholesterol screening program is set up in
the downtown area during the lunch hour. Individuals can walk in and have their cholesterol levels
determined for free. One hundred and seventy three people use the service, and their average
cholesterol is 217.8. The sample obtained is an example of
a. | a simple random sample, since the experimenter did not
know beforehand which individuals would come to the screening. | b. | a stratified sample of high and low cholesterol
individuals. | c. | a sample probably
containing bias and undercoverage. | d. | a multistage
sample of varying cholesterol levels. | e. | a systematic random
sample |
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6.
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You are testing a new medication for relief of
depression. You are going to give the new medication to subjects suffering from depression and see if
their symptoms have lessened after a month. You have eight subjects available. Half of the subjects
are to be given the new medication and the other half a placebo. The names of the eight subjects are
given below.
1. Blumenthal | 5. House | 2. Costello | 6.
Long | 3.
Duvall | 7. Pavlicova | 4. Fan | 8. Tang | | |
Using the list of
random digits
81507 27102 56027 55892 33063 41842 81868 71035 09001
43367 49497
starting at the beginning of this list and using single-digit labels, you
assign the first four subjects selected to receive the new medication, while the remainder receive
the placebo. The subjects assigned to the placebo are
a. | Blumenthal, Costello, Duvall, and
Fan. | b. | Blumenthal, House, Pavlicova, and
Tang. | c. | House, Long, Pavlicova, and
Tang. | d. | Costello, Duvall, Fan, and
Long. | e. | Costello, House, Duvall and Long |
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7.
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A study of human development showed two types of
movies to groups of children. Crackers were available in a bowl, and the investigators compared the
number of crackers eaten by children watching the different kinds of movies. One kind of movie was
shown at 8 AM (right after the children had breakfast) and another at 11 AM (right before the
children had lunch). It was found that during the movie shown at 11 AM, more crackers were eaten than
during the movie shown at 8 AM. The investigators concluded that the different types of movies had an
effect on appetite.
The results cannot be trusted because
a. | the study was not double-blind. Neither the
investigators nor the children should have been aware of which movie was being
shown. | b. | the investigators were biased. They knew beforehand what
they hoped the study would show. | c. | the investigators
should have used several bowls, with crackers randomly placed in each. | d. | children do not eat
crackers while watching movies | e. | the time the movie
was shown is a confounding variable. |
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8.
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We say that the design of a study is biased if
which of the following is true?
a. | A racial or sexual preference is
suspected | b. | Random placebos have been
used | c. | Certain outcomes are systematically
favored | d. | The correlation is greater than 1 or less than
–1 | e. | None of the
above. |
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9.
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Consider an experiment to investigate the
effectiveness of different insecticides in controlling pests and their effects on subsequent yield.
What is the best reason for randomly assigning treatment levels (spraying or not spraying) to the
experimental units (farms)?
a. | Randomization makes the experiment easier to conduct
since we can apply the insecticide in any pattern rather than in a systematic
fashion. | b. | Randomization will tend to average out all other
uncontrolled factors such as soil fertility so that they are not confounded with the treatment
effects. | c. | Randomization makes the analysis easier since the data
can be collected and entered into the computer in any order. | d. | Randomization is required by statistical consultants before they will help you
analyze the experiment. | e. | Randomization
implies that it is not necessary to be careful during the experiment, during data collection, and
during data analysis. |
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10.
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A nutritionist wants to study the effect of storage
time (6, 12, and 18 months) on the amount of vitamin C present in freeze dried fruit when stored for
these lengths of time. Vitamin C is measured in milligrams per 100 milligrams of fruit. Six fruit
packs were randomly assigned to each of the three storage times. The treatment, experimental
unit, and response are respectively:
a. | A specific storage time, amount of vitamin C, a fruit
pack | b. | A fruit pack, amount of vitamin C, a specific storage
time | c. | Random assignment, a fruit pack, amount of vitamin
C | d. | A specific storage time, a fruit pack, amount of vitamin
C | e. | A specific storage time, the nutritionist, amount of
vitamin C |
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