Exam
Name___________________________________
SHORT ANSWER. Write the word or phrase that best completes each statement or answers the question.
Provide an appropriate response.
1)
An agricultural researcher wishes to compare the yield of four different varieties of wheat.
64 plots of land are available for an experiment. On each plot of land one of the varieties of
wheat will be grown. At the end of the experiment the yield for the different varieties will
be compared. 32 of the plots are at one site (site A) and the other 32 are at another site (site
B). The soil at site A differs significantly from the soil at site B. The researcher wishes to
design an experiment. In this example, why might a randomized block design, with
blocking by soil type, be preferable to a completely randomized design?
1)
Use the random number table in Appendix A to obtain the required list of random numbers.
2)
A magazine is awarding a cash prize for 10 winners in its competition. 470 of the
contestants have answered all the competition questions correctly. The magazine will pick
the 10 winners at random from among these 470 contestants. Construct a list of 10 random
numbers between 1 and 470 that can be used in obtaining the required simple random
sample. Use the random number table and use as your starting point the digits 270 in row
12, columns 5–7.
2)
3)
A market researcher is conducting a telephone poll. She has a list of 581 registered voters
and wishes to interview a random sample of 12 of them. Construct a list of 12 random
numbers between 1 and 581 that can be used in obtaining the required simple random
sample. Use the random number table and use as your starting point the digits 432 in row
13, columns 10–12.
3)
Provide an appropriate response.
4)
Give an example of a designed experiment. In your experiment, identify the experimental
units, the response variable, the factor(s), the levels of each factor, and the treatments.
4)
5)
Define the terms population and sample.
5)
6)
A college lecturer has devised a new method of teaching a particular mathematical concept
and wishes to try out this teaching method on a representative sample of his students.
There are 76 students in his class and he wishes to obtain a simple random sample of 25 of
them. Describe a method he could use to obtain the sample.
6)
7)
A college lecturer has devised a new method of teaching a particular mathematical concept
and wishes to try out this teaching method on a representative sample of his students.
There are 76 students in his class and he wishes to obtain a simple random sample of 25 of
them. Describe a method which would be unlikely to yield a representative sample.
7)
8)
Define observational study and experiment. Define the terms “treatment group” and
“control group” as part of your answer.
8)
9)
Define simple random sampling. Explain why this is important in design of experiments.
9)
10)
An education researcher wishes to assess the effectiveness of three different methods for
teaching young children to read. The 380 children participating in the study are divided
into three groups. The study runs for six months. The children in the first group are taught
using method A, the children in the second group are taught using method B, and the
children in the third group are taught using method C. At the end of the six months, the
reading ability of the children in the different groups is assessed. Why might
randomization be used when dividing the children into three groups?
10)
11)
Fill in the following blanks: The two major types of statistics are ______________ statistics
and ___________ statistics.
11)
12)
A researcher wishes to assess the working conditions of farm workers at farms in his
district. There are 37 farms in the district which are widely scattered geographically. The
researcher wishes to interview at least 300 farm workers. Describe a method for selecting a
sample which involves cluster sampling. Each farm employs approximately 50 workers.
12)
13)
Describe a double–blind experiment and explain why blinding is used. Define the term
“placebo effect” as part of the answer.
13)
14)
Describe the advantages and disadvantages of cluster sampling as compared with simple
random sampling.
14)
Use the random number table in Appendix A to obtain the required list of random numbers.
15)
A medical researcher is conducting clinical trials. Of the 60 people participating in the
trial, 20 will receive a placebo, 20 will receive the experimental drug, and 20 will constitute
the control group. The 20 people who will receive the drug will be selected at random.
Construct a list of 20 random numbers between 1 and 60 which can be used in obtaining
the required simple random sample. Use the random number table and use as your
starting point the digits 54 in row 15, columns 20–21.
15)
Provide an appropriate response.
16)
Describe the steps involved when using stratified random sampling with proportional
allocation. What are the advantages of this sampling method?
16)
17)
An agricultural researcher wishes to compare the yield of four different varieties of wheat.
64 plots of land are available for an experiment. On each plot of land one of the varieties of
wheat will be grown. At the end of the experiment the yield for the different varieties will
be compared. 32 of the plots are at one site (site A) and the other 32 are at another site (site
B). The soil at site A differs significantly from the soil at site B. If the researcher wishes to
design an experiment using completely randomized design, how could the wheat varieties
be assigned to the different plots?
17)
Use the random number table in Appendix A to obtain the required list of random numbers.
18)
A company employs 5382 people and wishes to interview a random sample of 14 of them
with regard to the company‘s health insurance policy. Construct a list of 14 random
numbers between 1 and 5382 that can be used in obtaining the required simple random
sample. Use the random number table and use as your starting point the digits 0691 in row
3, columns 30–33.
18)
Provide an appropriate response.
19)
Define observational study and designed experiment.
19)
20)
A political researcher wishes to gauge political sentiment regarding a proposed tax cut. He
obtains a list of 1000 email addresses from an internet provider, uses a random number
table to select a random sample of 100 of these addresses, emails the people in the sample
and requests that they respond to his questions by email. Do you think that the group of
people who respond is likely to be representative of all registered voters? Explain your
answer.
20)
21)
Which method of sampling is easier: simple random sampling or systematic random
sampling?
21)
22)
At one hospital in 1992, 674 women were diagnosed with breast cancer. Five years later,
88% of the Caucasian women and 63% of the African American women were still alive.
This observational study shows an association between race and breast cancer
survival—that Caucasian women are more likely to survive breast cancer than African
American women. How could this study be modified to make it a designed experiment?
Comment on the feasibility of the designed experiment that you described.
22)
23)
Why do statisticians sometimes use inferential statistics to draw conclusions about a
population? In what situations might a statistician draw conclusions about a population
using descriptive statistics only?
23)
24)
Define the terms “stratified sampling”, “systematic sampling” and “cluster sampling”. Give
examples for each.
24)
25)
Explain the difference between an observational study and a designed experiment.
25)
26)
The residents of one town are classified by a social scientist as follows.
Lower income: 4320
Middle income: 1520
Upper income: 2160
The scientist wishes to pick a sample of 200 of the residents for a study. Describe a method
for selecting the sample which involves stratified sampling with proportional allocation.
26)
27)
In a designed experiment, explain the difference between the treatments and the factors.
27)
28)
In a clinical trial, each participant will receive a placebo, a low dosage of a drug, or a high
dosage of the drug. The participants consist of 90 men and 90 women. The 90 men are
randomly divided into three groups of 30 men each. Each group of men is randomly
assigned to a different treatment (placebo, low dose, or high dose). Likewise, the 90 women
are randomly divided into three groups of 30 women each. Each group of women is
randomly assigned to a different treatment (placebo, low dose, or high dose). Is this a
completely randomized design or a randomized block design? Explain your answer.
28)
29)
A tax auditor has a pile of 191 tax returns of which he would like to select 17 for a special
audit. Describe a method for selecting the sample which involves systematic random
sampling.
29)
30)
A store manager wishes to determine whether his customers would be prepared to pay a
little extra for organic produce. He uses a random number table to choose 50 random
numbers between 1 and 200. He stands outside the store on a Monday morning between
9:00 a.m. and 12:00 noon and interviews the people corresponding to the random numbers.
For example random number 82 would correspond to the 82nd person to arrive. Do you
think that the sample obtained in this way will be representative of all the store‘s
customers?
30)
31)
An agricultural researcher wishes to compare the yield of four different varieties of wheat.
64 plots of land are available for an experiment. On each plot of land one of the varieties of
wheat will be grown. At the end of the experiment the yield for the different varieties will
be compared. 32 of the plots are at one site (site A) and the other 32 are at another site (site
B). The soil at site A differs significantly from the soil at site B. If the researcher wishes to
design an experiment using randomized block design, how could the wheat varieties be
assigned to the different plots?
31)
32)
A study was conducted to evaluate the effectiveness of a new diet pill for men. A group of
3000 men were involved in the study. Of these 3000 men, 2311 took the diet pill and 889
were given a placebo. Identify the treatments, the treatment group, and the control group.
32)
33)
Define probability sampling. Identify some advantages of probability sampling.
33)
34)
The effects of global warming on the planet have received increased national attention in
recent years. But how many U.S. adults would be willing to change certain personal
behaviors in order to help reverse the effects of global warming? A major pollster
conducted a telephone poll of 1060 U.S. adults to determine the answer to the following
questions: (1) Is public transportation a viable option for you? (2) If not, do you own a
hybrid vehicle or one that gets more than an overall average of 30 miles per gallon? (3) If
not, would you be willing to purchase a hybrid vehicle within the five years? Respondents
were also asked questions about age, sex, race, education, region, and household income to
ensure that results represented a cross section of U.S. adults.
i) What kind of sampling design was used in this survey? Explain your answer.
ii) If 86% of the respondents answered the first question in the negative, what was the
approximate sample size for the second question?
iii) If 71% of those responding to the second question answered “no,” what was the
approximate size for the third question?
34)
MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.
35)
The human resources department of a large, well–known telecommunications firm is behind
schedule in sampling the job satisfaction of the company’s employees. In an effort to catch–up, the
HR manager quickly goes down an alphabetical list of employees and e–mails a survey to every
tenth employee. An neutral third party collects all surveys and ensures all of the selected
employees respond to the survey. What sampling method best describes what the HR manager is
doing?
35)
A)
Systematic sampling
B)
Cluster sampling
C)
Stratified sampling
D)
Multistage sampling
A designed experiment is described. Identify the specified element of the experiment.
36)
In a clinical trial, 780 participants suffering from high blood pressure were randomly assigned to
one of three groups. Over a one–month period, the first group received a low dosage of an
experimental drug, the second group received a high dosage of the experimental drug, and the
third group received a placebo. The diastolic blood pressure of each participant was measured at
the beginning and at the end of the period and the change in blood pressure was recorded. Identify
the treatments.
36)
A)
Diastolic blood pressure at start, diastolic blood pressure at end
B)
Placebo, low dosage of drug, high dosage of drug
C)
The experimental drug
D)
Low dosage of drug, high dosage of drug
Provide an appropriate response.
37)
The table below shows the total number of births in the U.S. and the birth rate per 1,000 population
in each of the years 1990–1994.
Year Births Birth Rate
1990 4,158,512 16.7
1991 4,110,907 16.3
1992 4,065,014 15.9
1993 4,000,240 15.5
1994 3,979,000 15.3
Classify the study as either descriptive or inferential.
37)
A)
Descriptive
B)
Inferential
38)
Thirty of the 198 students enrolled in Statistics 101 were asked if they wanted Exam II to be a
take–home or an in–class assessment. Twenty, or about 67%, of the students polled indicated a
preference for an in–class exam. The professor concluded that the majority of students in Statistics
101 would prefer an in–class examination for the second assessment. Did the professor perform a
descriptive study or an inferential study?
38)
A)
Descriptive
B)
Inferential
39)
The table below shows the number of new AIDS cases in the U.S. in each of the years 1989–1994.
Year New AIDS cases
1989 33,643
1990 41,761
1991 43,771
1992 45,961
1993 103,463
1994 61,301
Classify the study as either descriptive or inferential.
39)
A)
Descriptive
B)
Inferential
Answer the question.
40)
A magazine publisher always mails out a questionnaire six months before a subscription ends.
This questionnaire asks its subscribers if they are going to renew their subscriptions. On average,
only 8% of the subscribers respond to the questionnaire. Of the 8% who do respond, an average of
41% say that they will renew their subscription. This 8% who respond to the questionnaire are
known as what?
40)
A)
The population
B)
The sample
List all possible samples from the specified population.
41)
Given a group of students: Allen (A), Brenda (B), Chad (C), Dorothy (D), and Eric (E), list all of the
possible samples (without replacement) of size four that can be obtained from the group.
41)
A)
A,B,C,D A,B,C,E A,C,D,E A,D,E,B
B)
A,B,C,D A,B,C,E A,C,D,E A,D,E,B B,C,D,E B,C,E,A B,D,E,A
C,A,B,D C,E,D,B D,A,C,E
C)
A,B,C,D
D)
A,B,C,D A,B,C,E A,C,D,E A,D,E,B B,C,D,E
A designed experiment is described. Identify the specified element of the experiment.
42)
An education researcher was interested in examining the effect of the teaching method and the
effect of the particular teacher on students’ scores on a reading test. In a study, there are four
different teachers (Juliana, Felix, Sonia, and Helen) and three different teaching methods (method
A, method B, and method C). The number of students participating in the study is 258. Students are
randomly assigned to a teaching method and teacher. Identify the levels of the factor “teaching
method“.
42)
A)
Juliana, Felix, Sonia, and Helen
B)
Method A, method B, method C
C)
Score on reading test
D)
Teaching method and teacher
Identify the study as an observational study or a designed experiment.
43)
A researcher wished to assess the importance of exercise in weight–loss programs. 412 people, all
considered to be at least 20 pounds overweight, volunteered to participate in a study. The
participants were randomly assigned to one of two groups. Over a two–month period, the first
group followed a particular diet but were instructed to perform no exercise other than walking.
The second group followed the same diet but also performed aerobic exercise for one hour each
day. At the end of the two months, the weight loss of each participant was recorded. The average
weight loss was calculated for each group and it was found that the average weight loss for the
second group was significantly greater than the average weight loss for the first group.
43)
A)
Designed experiment
B)
Observational study
Provide an appropriate response.
44)
The table below shows the number of homicides in the U.S. in each of the years 1989–1993.
Year
Murder and non–negligent
manslaughter
Number of offenses
1989 21,500
1990 23,440
1991 24,700
1992 23,760
1993 24,530
Classify the study as either descriptive or inferential.
44)
A)
Descriptive
B)
Inferential
Answer the question.
45)
In a poll of 50,000 randomly selected college students, 74% answered “yes” when asked “Do you
have a television in your dorm room?” Identify the sample and population.
45)
A)
Sample: all college students; population: the 50,000 selected college students
B)
Sample: the 50,000 selected college students; population: the 74% who answered “yes”
C)
Sample: the 50,000 selected college students; population: all college students
D)
Sample: the 74% who answered “yes”; population: all college students
46)
A computer network manager wants to test the reliability of some new and expensive fiber–optic
Ethernet cables that computer department just received. The computer department received 7
boxes containing 10 cables each. The manager does not have the time to test every cable in each
box. The manager will choose one box at random and test 2 cables chosen randomly within that
box. What is the sample?
46)
A)
The 7 boxes
B)
The 2 cables chosen for testing
C)
The one box that was chosen at random from the 7 boxes
D)
70 cables
List all possible samples from the specified population.
47)
The members of a board of directors have the following roles: president (P), vice president (V),
secretary (S), treasury (T), and fundraiser (F). Consider these board members to be a population of
interest. List the 10 possible samples (without replacement) of size two from this population of five
board members.
47)
A)
P,V P,S P,T P,F V,S V,T V,F S,T S,F T,F
B)
P,P P,V P,S P,T P,F V,V V,S V,T V,F S,S
C)
S,T S,F T,P T,V T,S T,F F,P F,V F,S F,T
D)
P,V P,S P,T P,F V,P V,S V,T V,F S,P S,V
Identify the study as an observational study or a designed experiment.
48)
An educational researcher used school records to determine that, in one school district, 84% of
children living in two–parent homes graduated high school while 75% of children living in
single–parent homes graduated high school.
48)
A)
Designed experiment
B)
Observational study
A designed experiment is described. Identify the specified element of the experiment.
49)
In a clinical trial, 780 participants suffering from high blood pressure were randomly assigned to
one of three groups. Over a one–month period, the first group received a low dosage of an
experimental drug, the second group received a high dosage of the drug, and the third group
received a placebo. The diastolic blood pressure of each participant was measured at the beginning
and at the end of the period and the change in blood pressure was recorded. Identify the
experimental units (subjects).
49)
A)
The three different groups
B)
The treatment (i.e., placebo, low dosage of drug, or high dosage of drug)
C)
The diastolic blood pressures of the participants
D)
The participants in the experiment
Identify the study as an observational study or a designed experiment.
50)
An examination of the medical records of 10, 000 women showed that those who were short and
fair skinned had a higher risk of osteoperosis.
50)
A)
Designed experiment
B)
Observational study
B
51)
In a clinical trial, 780 participants suffering from high blood pressure were randomly assigned to
one of three groups. Over a one–month period, the first group received the experimental drug, the
second group received a placebo, and the third group received no treatment. The diastolic blood
pressure of each participant was measured at the beginning and at the end of the period and the
change in blood pressure was recorded. The average change in blood pressure was calculated for
each of the three groups and the three averages were compared.
51)
A)
Designed experiment
B)
Observational study
A
Answer the question.
52)
A magazine publisher mails a survey to every subscriber asking about the quality of its
subscription service. The total number of subscribers represents what?
52)
A)
The population
B)
The sample
A
D
Provide an appropriate response.
53)
The finalists in an essay competition are Lisa (L), Melina (M), Ben (B), Danny (D), Eric (E), and
Joan (J). Consider these finalists to be a population of interest. The possible samples (without
replacement) of size two that can be obtained from this population of six finalists are as follows.
L,M L,B L,D L,E L,J M,B M,D
M,E M,J B,D B,E B,J D,E D,J E,J
If a simple random sampling method is used to obtain a sample of two of the finalists, what are the
chances of selecting Lisa and Danny?
53)
A)
2
15
B)
1
6
C)
1
15
D)
1
3
A designed experiment is described. Identify the specified element of the experiment.
54)
A herpetologist performed a study on the effects of the body type and mating call of the male
bullfrog as signals of quality to mates. Four life–sized dummies of male bullfrogs and two sound
recordings provided a tool for testing female response to the unfamiliar frogs whose bodies varied
by size (large or small) and color (dark or light) and whose mating calls varied by pitch (high,
normal, or low). The female bullfrogs were observed to see whether they approached each of the
four life–sized dummies. Identify the factor(s).
54)
A)
Large or small, dark or light, high pitch, normal pitch, or low pitch
B)
Body size, body color, and mating call pitch
C)
Body type and mating call
D)
Whether or not (yes or no) the female frogs approached a male dummy
B
Identify the study as an observational study or a designed experiment.
55)
At one hospital in 1992, 674 women were diagnosed with breast cancer. Five years later, 88% of the
Caucasian women and 83% of the African American women were still alive.
55)
A)
Designed experiment
B)
Observational study
B
56)
In a group of 500 men and women, those who smoked did worse on tests of reaction time than
those who did not smoke.
56)
A)
Designed experiment
B)
Observational study
B
C
Answer the question.
57)
100,000 randomly selected adults were asked whether they drink at least 48 oz of water each day
and only 45% said yes. Identify the sample and population.
57)
A)
Sample: the 100,000 selected adults; population: all adults
B)
Sample: all adults ; population: the 100,000 selected adults
C)
Sample: the 45% of adults who drink at least 48 oz of water; population: all adults
D)
Sample: the 100,000 selected adults; population: the 45% of adults who drink at least 48 oz of
water
58)
The spell–checker in a desktop publishing application may not catch all misspellings (e.g. their,
there) or correctly interpret the spellings of proper names. Jackie is an expert editor and can
proofread extremely quickly. Jackie is hired by a book publisher to check the spelling of every
word in the latest proof of a history book. With regard to Jackie’s assignment, what is the
population?
58)
A)
Every word in the latest proof of the history book
B)
Finding misspellings in the latest proof of the history book
C)
The total number of misspellings that Jackie finds in the latest proof of the history book
D)
The latest proof of the history book
Provide an appropriate response.
59)
A news article appearing in a national paper stated that “The fatality rate from use of firearms sank
to a record low last year, the government estimated Friday. But the overall number of violent
fatalities increased slightly, leading the government to urge an increase in police forces in major
urban areas. Overall, 15,600 people died from violent crimes in 2005, up from 15,562 in 2004,
according to projections from a government source. Is the figure15,600 a descriptive statistic or an
inferential statistic? Is the figure 15,562 a descriptive statistic or an inferential statistic?
59)
A)
The figure15,600 is an inferential statistic since it is indicated in the statement that it is a
projection (probably based on incomplete data for the year 2004). The figure15,562 is an
inferential statistic as well.
B)
The figure15,600 is an inferential statistic since it is indicated in the statement that it is a
projection (probably based on incomplete data for the year 2005). The figure 15,562 is a
descriptive statistic since it reflects the actual number of deaths from violent crimes for the
year 2004.
C)
The figure15,600 is a descriptive statistic since it reflects the actual number of deaths from
violent crimes for the year 2005. The figure15,562 is a descriptive statistic as well.
D)
The figure15,600 is a descriptive statistic since it reflects the actual number of deaths from
violent crimes for the year 2004. The figure15,562 is an inferential statistic since it is indicated
in the statement that it is a projection (probably based on incomplete data for the year 2005).
A designed experiment is described. Identify the specified element of the experiment.
60)
In a clinical trial, 780 participants suffering from high blood pressure were randomly assigned to
one of three groups. Over a one–month period, the first group received a low dosage of an
experimental drug, the second group received a high dosage of the drug, and the third group
received a placebo. The diastolic blood pressure of each participant was measured at the beginning
and at the end of the period and the change in blood pressure was recorded. Identify the response
variable.
60)
A)
Change in diastolic blood pressure
B)
The treatment received (placebo, low dosage, high dosage)
C)
The dosage of the drug
D)
The participants in the experiment
Provide an appropriate response.
61)
The members of a board of directors have the following roles: president (P), vice president (V),
secretary (S), treasury (T), and fundraiser (F). Consider these board members to be a population of
interest. The possible samples (without replacement) of size two that can be obtained from these
five board members are as follows.
P,V P,S P,T P,F V,S V,T V,F S,T S,F T,F
If a simple random sampling method is used to obtain a sample of two of the board members, what
are the chances of selecting the secretary and the treasurer?
61)
A)
1
20
B)
2
5
C)
1
5
D)
1
10
A designed experiment is described. Identify the specified element of the experiment.
62)
In a clinical trial, 780 participants suffering from high blood pressure were randomly assigned to
one of three groups. Over a one–month period, the first group received a low dosage of an
experimental drug, the second group received a high dosage of the drug, and the third group
received a placebo. The diastolic blood pressure of each participant was measured at the beginning
and at the end of the period and the change in blood pressure was recorded. Identify the levels of
the factor.
62)
A)
High blood pressure, low blood pressure
B)
The experimental drug
C)
Placebo, low dosage, high dosage
D)
Diastolic blood pressure at the start, diastolic blood pressure at the end
Answer the question.
63)
George, a network engineer, ordered 500 CAT 5e Ethernet cables for use at his company’s network.
After receiving these cables, he decided to randomly test 150 of these cables before using them. He
was alarmed to find out that 92% of these cables failed completely. He returned the entire lot to the
manufacturer. When he tested the cables, what was George’s sample?
63)
A)
150 cables
B)
138 cables
C)
500 cables
D)
460 cables
Provide an appropriate response.
64)
Several watch–dog consumer groups have criticized the fast food industry for serving food with
excessive fat content. One watch–dog announced that it will randomly select one fast food chain
per week. The watch–dog will then decide, as a group, to purchase one item off the menu that has
been advertised the most on television and in the newspapers. The watch–dog will then have that
heavily–advertised, just–purchased item professionally sampled for fat content. Weekly results
will be posted on the watch–dog’s website. For this scenario, what best describes the watch–dog’s
sampling activities each week?
64)
A)
Stratified sampling
B)
Systematic sampling
C)
Multistage sampling
D)
Cluster sampling
65)
At a college there are 120 freshmen, 90 sophomores, 110 juniors, and 80 seniors. A school
administrator selects a simple random sample of 12 of the freshmen, a simple random sample of 9
of the sophomores, a simple random sample of 11 of the juniors, and a simple random sample of 8
of the seniors. She then interviews all the students selected. Identify the type of sampling used in
this example.
65)
A)
Cluster sampling
B)
Systematic random sampling
C)
Simple random sampling
D)
Stratified sampling
A designed experiment is described. Identify the specified element of the experiment.
66)
An education researcher was interested in examining the effect of the teaching method and the
effect of the particular teacher on students’ scores on a reading test. In a study, there are four
different teachers (Juliana, Felix, Sonia, and Helen) and three different teaching methods (method
A, method B, and method C). The number of students participating in the study is 258. Students are
randomly assigned to a teaching method and teacher. Identify the response variable.
66)
A)
Score on reading test
B)
Teaching method
C)
Teacher
D)
Method A, method B, method C
Provide an appropriate response.
67)
Based on a random sample of 1000 people, a researcher obtained the following estimates of the
percentage of people lacking health insurance in one U.S. city.
Age Percentage not covered
18–24 28.2
25–39 24.9
40–54 19.1
55–65 16.5
Classify the study as either descriptive or inferential.
67)
A)
Descriptive
B)
Inferential
68)
The table below shows the average income by age group for the residents of one town in the year
1998. The average incomes for each age group are estimates based on a sample of size 100 from
each group.
Age group Average income
18–24 $17,180
25–39 $26,661
40–54 $32,471
55–70 $25,960
Over 70 $18,241
Classify the study as either descriptive or inferential.
68)
A)
Descriptive
B)
Inferential
List all possible samples from the specified population.
69)
The finalists in an essay competition are Lisa (L), Melina (M), Ben (B), Danny (D), Eric (E), and
Joan (J). Consider these finalists to be a population of interest. List the 20 possible samples (without
replacement) of size three from this population of six finalists.
69)
A)
L,M,B L,M,D L,M,E L,M,J L,B,D L,B,E L,B,J L,D,E L,D,J L,L,M
M,B,D M,B,E M,B,J M,D,E M,D,J M,M,J B,D,E B,B,J B,E,J D,D,J
B)
L,M,B L,M,D L,M,E L,M,J L,B,D L,B,E L,B,J L,D,E L,D,J L,E,J
M,B,D M,B,E M,B,J M,D,E M,D,J M,E,J M,L,B M,L,D M,L,J B,D,E
C)
L,M,B L,M,D L,M,E L,M,J L,B,D L,B,E L,B,J L,D,E L,D,J L,E,J
L,L,M L,L,B L,L,D L,L,E L,L,J M,M,B M,M,D M,M,E M,M,J B,B,D
D)
L,M,B L,M,D L,M,E L,M,J L,B,D L,B,E L,B,J L,D,E L,D,J L,E,J
M,B,D M,B,E M,B,J M,D,E M,D,J M,E,J B,D,E B,D,J B,E,J D,E,J
Provide an appropriate response.
70)
A researcher randomly selects a sample of 100 students from the students enrolled at a particular
college. She asks each student his age and calculates the mean age of the 100 students. It is
21.3 years. Based on this sample, she then estimates the mean age of all students enrolled at the
college to be 21.3 years. In what way are descriptive statistics involved in this example? In what
way are inferential statistics involved?
70)
A)
When calculating the mean age of the students in the sample, the researcher is using
descriptive statistics. When estimating the mean age of all students at the college, the
researcher is using inferential statistics.
B)
When calculating the mean age of the students in the sample, the researcher is using
inferential statistics. When estimating the mean age of all students at the college, the
researcher is using descriptive statistics.
Identify the study as an observational study or a designed experiment.
71)
A political pollster reports that his candidate has a 10% lead in the polls with 10% undecided.
71)
A)
Designed experiment
B)
Observational study
B
72)
A clinic gives a drug to a group of ten patients and a placebo to another group of ten patients to
find out if the drug has an effect on the patients’ illness.
72)
A)
Designed experiment
B)
Observational study
A
Provide an appropriate response.
73)
From a group of 496 students, every 49th student starting with the 3rd student is selected. Identify
the type of sampling used in this example.
73)
A)
Stratified sampling
B)
Cluster sampling
C)
Systematic random sampling
D)
Simple random sampling
C
74)
A meteorologist constructs a graph showing the total precipitation in Phoenix, Arizona in each of
the months of 1998. Does this involve descriptive statistics or inferential statistics?
74)
A)
Descriptive
B)
Inferential
A
A
Answer the question.
75)
An employee at the local ice cream parlor asks three customers if they like chocolate ice cream.
Identify the sample and population.
75)
A)
Sample: the 3 selected customers; population: the customers who like chocolate ice cream
B)
Sample: the customers who like chocolate ice cream; population: all customers
C)
Sample: all customers; population: the 3 selected customers
D)
Sample: the 3 selected customers; population: all customers
List all possible samples from the specified population.
76)
The finalists in an essay competition are Lisa (L), Melina (M), Ben (B), Danny (D), Eric (E), and
Joan (J). Consider these finalists to be a population of interest. List the 15 possible samples (without
replacement) of size two from this population of six finalists.
76)
A)
L,L L,M L,B L,D L,E L,J M,M M,B
M,D M,E M,J B,B B,D B,E B,J
B)
L,M L,B L,D L,E L,J M,B M,D
M,E M,J B,D B,E B,J D,E D,J E,J
C)
D,D D,E D,J E,L E,M E,B E,D E,E E,J J,L J,M J,B J,D J,E J,J
D)
L,L L,M L,B L,D L,E L,J M,L M,M
M,B M,D M,E M,J B,L B,M B,B
Identify the study as an observational study or a designed experiment.
77)
400 patients suffering from chronic back pain were randomly assigned to one of two groups. Over a
four–month period, the first group received acupuncture treatments and the second group received
a placebo. Patients who received acupuncture treatments improved more than those who received
the placebo.
77)
A)
Designed experiment
B)
Observational study
Answer the question.
78)
A magazine publisher mails a survey to every subscriber asking about the timeliness of its
subscription service. The publisher finds that only 4% of the subscribers responded. This 4%
represents what?
78)
A)
The population
B)
The sample
Provide an appropriate response.
79)
A statistics student’s presentation of the results of her study included many charts, graphs, and
tables. Identify the kind of statistical study conducted.
79)
A)
The study was necessarily inferential.
B)
The study was purely descriptive.
C)
The purpose of the study may have been completely descriptive or it might have been
inferential.
A designed experiment is described. Identify the specified element of the experiment.
80)
A herpetologist performed a study on the effects of the body type and mating call of the male
bullfrog as signals of quality to mates. Four life–sized dummies of male bullfrogs and two sound
recordings provided a tool for testing female response to the unfamiliar frogs whose bodies varied
by size (large or small) and color (dark or light) and whose mating calls varied by pitch (high,
normal, or low). The female bullfrogs were observed to see whether they approached each of the
four life–sized dummies. Identify the levels of each factor.
80)
A)
Body size has three levels: large, medium, and small. Body color has three levels: dark,
medium, and light. Mating call pitch has three levels: high, normal, and low.
B)
There are three levels: body size, body color, and mating call pitch
C)
Body size has two levels: large and small. Body color has two levels: dark and light. Mating
call pitch has three levels: high, normal, and low.
D)
Body size has three levels: large, medium, and small. Body color has three levels: dark,
medium, and light. Mating call pitch has two levels: high and low.
Provide an appropriate response.
81)
A mega–discount chain store just opened a new clothing store in town emphasizing mainly
women’s clothing. Before opening, management had to decide whether to only carry either men’s,
women’s, boys’, girls‘, or infants’ clothing. After performing representative sampling of potential
customers from each of these groups, it was decided to carry only women’s clothing. Identify the
type of sampling used in this example.
81)
A)
Cluster sampling
B)
Multistage sampling
C)
Systematic sampling
D)
Stratified sampling
A designed experiment is described. Identify the specified element of the experiment.
82)
A herpetologist performed a study on the effects of the body type and mating call of the male
bullfrog as signals of quality to mates. Four life–sized dummies of male bullfrogs and two sound
recordings provided a tool for testing female response to the unfamiliar frogs whose bodies varied
by size (large or small) and color (dark or light) and whose mating calls varied by pitch (high,
normal, or low). The female bullfrogs were observed to see whether they approached each of the
four life–sized dummies. Identify the experimental units.
82)
A)
All of the frogs, male and female
B)
The male bullfrogs
C)
The female bullfrogs
D)
The scientist
Provide an appropriate response.
83)
A newly–premiered play just ended that evening at a local theater. Theater management briefly
interviews every ninth person leaving the theater to see if that person will recommend the play at
that theater to other people. Identify the type of sampling used in this example.
83)
A)
Multistage sampling
B)
Systematic sampling
C)
Stratified sampling
D)
Cluster sampling
B
84)
True or false? In simple random sampling, each possible sample is equally likely to be the one
obtained.
84)
A)
True
B)
False
A
A designed experiment is described. Identify the specified element of the experiment.
85)
A herpetologist performed a study on the effects of the body type and mating call of the male
bullfrog as signals of quality to mates. Four life–sized dummies of male bullfrogs and two sound
recordings provided a tool for testing female response to the unfamiliar frogs whose bodies varied
by size (large or small) and color (dark or light) and whose mating calls varied by pitch (high,
normal, or low). The female bullfrogs were observed to see whether they approached each of the
four life–sized dummies. Identify the response variable.
85)
A)
Whether or not the male frogs were large and light–colored
B)
Large and small; dark and light; call and no call
C)
The four life–sized dummy male bullfrogs
D)
Whether or not (yes or no) the female frogs approached a male dummy
D
C
Provide an appropriate response.
86)
A pollster uses a computer to generate 500 random numbers and then interviews the voters
corresponding to those numbers. Identify the type of sampling used in this example.
86)
A)
Cluster sampling
B)
Stratified sampling
C)
Simple random sampling
D)
Systematic random sampling
List all possible samples from the specified population.
87)
The six members of a board of directors are Sam (S), Laurie (L), Peggy (P), Jorges (J), Max (M), and
Claude (C). Consider these board members to be a population of interest. List the 15 possible
samples (without replacement) of size four from this population of six board members.
87)
A)
S,L,P,J S,L,P,M S,L,P,C S,L,J,M S,L,J,C S,L,M,C S,J,M,C L,P,J,M
L,S,P,J P,P,J,M L,P,J,C L,P,M,C L,J,M,C P,S,M,C P,J,M,C
B)
S,S,L,P S,L,P,J S,L,P,M S,L,P,C S,L,J,M S,P,J,M S,P,J,C S,P,M,C
S,J,M,C L,L,P,J L,P,J,M L,P,J,C L,P,M,C L,J,M,C P,J,M,C
C)
S,L,P,J S,L,P,M S,L,P,C S,L,J,M S,L,J,C S,L,M,C S,P,J,M S,P,J,C
S,P,M,C S,J,M,C L,P,J,M L,P,J,C L,P,M,C L,J,M,C P,J,M,C
D)
S,L,P,J S,L,P,M S,L,P,C S,P,J,M S,P,J,C S,P,M,C S,J,M,C L,S,P,J
L,P,J,M L,P,J,C L,P,M,C L,J,M,C P,S,J,M P,J,M,C J,S,M,C
Identify the study as an observational study or a designed experiment.
88)
A doctor induces a cardiac stress test to determine the reason for a patient’s illness.
88)
A)
Designed experiment
B)
Observational study
Provide an appropriate response.
89)
The finalists in an essay competition are Lisa (L), Melina (M), Ben (B), Danny (D), Eric (E), and
Joan (J). Consider these finalists to be a population of interest. The possible samples (without
replacement) of size three that can be obtained from this population of six finalists are as follows.
L,M,B L,M,D L,M,E L,M,J L,B,D L,B,E
L,B,J L,D,E L,D,J L,E,J M,B,D M,B,E
M,B,J M,D,E M,D,J M,E,J B,D,E B,D,J
B,E,J D,E,J
If a simple random sampling method is used to obtain a sample of three of the finalists, what are
the chances of selecting Ben, Danny, and Joan?
89)
A)
1
20
B)
1
2
C)
1
3
D)
3
20
A designed experiment is described. Identify the specified element of the experiment.
90)
A herpetologist performed a study on the effects of the body type and mating call of the male
bullfrog as signals of quality to mates. Four life–sized dummies of male bullfrogs and two sound
recordings provided a tool for testing female response to the unfamiliar frogs whose bodies varied
by size (large or small) and color (dark or light) and whose mating calls varied by pitch (high,
normal, or low). The female bullfrogs were observed to see whether they approached each of the
four life–sized dummies. Identify the treatments.
90)
A)
The twelve different possible combinations of the three body sizes, two body colors, and two
mating call pitches
B)
The eighteen different possible combinations of the two body sizes, three body colors, and
three mating call pitches
C)
The twelve different possible combinations of the two body sizes, two body colors, and three
mating call pitches
D)
The eight different possible combinations of the two body sizes, two body colors, and two
mating call pitches
Provide an appropriate response.
91)
Before premiering a blockbuster movie at a theater, test screenings are done beforehand. A small
number of selected theaters are chosen geographically throughout the country. Each theater chosen
is supposed to be representative of theatergoers in that area. Everyone is interviewed when the
movie is over. Identify the type of sampling used in this example.
91)
A)
Attempted census
B)
Systematic sampling
C)
Cluster sampling
D)
Stratified sampling
A designed experiment is described. Identify the specified element of the experiment.
92)
An education researcher was interested in examining the effect of the teaching method and the
effect of the particular teacher on students’ scores on a reading test. In a study, there are four
different teachers (Juliana, Felix, Sonia, and Helen) and three different teaching methods (method
A, method B, and method C). The number of students participating in the study is 258. Students are
randomly assigned to a teaching method and teacher. Identify the factors.
92)
A)
Juliana, Felix, Sonia, and Helen
B)
Score on reading test
C)
Method A, method B, method C
D)
Teaching method and teacher
93)
In a clinical trial, 780 participants suffering from high blood pressure were randomly assigned to
one of three groups. Over a one–month period, the first group received a low dosage of an
experimental drug, the second group received a high dosage of the drug, and the third group
received a placebo. The diastolic blood pressure of each participant was measured at the beginning
and at the end of the period and the change in blood pressure was recorded. Identify the factor.
93)
A)
The participants in the experiment
B)
The dosage of the drug
C)
Diastolic blood pressure
D)
The experimental drug
94)
An education researcher was interested in examining the effect of the teaching method and the
effect of the particular teacher on students’ scores on a reading test. In a study, there are four
different teachers (Juliana, Felix, Sonia, and Helen) and three different teaching methods (method
A, method B, and method C). The number of students participating in the study is 258. Students are
randomly assigned to a teaching method and teacher. Identify the experimental units (subjects).
94)
A)
The three groups of students (those assigned to method A, those assigned to method B, and
those assigned to method C)
B)
The 258 students participating in the study
C)
Method A, method B, method C
D)
Teaching method and teacher
Provide an appropriate response.
95)
Geologists have an interest in the structure and the history of the earth. A geologist can go back in
time by drilling deep into the ground, retrieving a core sample, estimating the ages of the various
layers, and examining the composition. A timeline can be built of the entire area from where the
core sample was drilled. A geologist may retrieve several core samples to confirm the history of
the earth’s structure in that sampled area. Mountains, lakes, and unstable ground can easily
impede a simple random sampling of a desired geographical area, therefore what is the most
realistic sampling method that represents the actual drillings, comparisons, and scientific
examinations of several core samples within the same geographical area?
95)
A)
Systematic sampling
B)
Cluster sampling
C)
Multistage sampling
D)
Stratified sampling
A designed experiment is described. Identify the specified element of the experiment.
96)
An education researcher was interested in examining the effect of the teaching method and the
effect of the particular teacher on students‘ scores on a reading test. In a study, there are two
different teachers (Juliana and Felix) and three different teaching methods (method A, method B,
and method C). The number of students participating in the study is 258. Students are randomly
assigned to a teaching method and teacher. Identify the treatments.
96)
A)
Juliana and method A, Juliana and method B, Juliana and method C, Felix and method A,
Felix and method B, Felix and method C
B)
Method A, method B, method C
C)
Juliana, Felix, Sonia, and Helen
D)
Teaching method and teacher
Answer the question.
97)
A computer network manager wants to test the reliability of some new and expensive fiber–optic
Ethernet cables that the computer department just received. The computer department received 4
boxes containing 40 cables each. The manager does not have the time to test every cable in each
box. The manager will choose one box at random and test 8 cables chosen randomly within that
box. What is the population?
97)
A)
The one box that was chosen at random from the 4 boxes
B)
160 cables
C)
The 4 boxes
D)
The 8 cables chosen randomly for testing
Provide an appropriate response.
98)
An education researcher randomly selects 38 schools from one school district and interviews all the
teachers at each of the 38 schools. Identify the type of sampling used in this example.
98)
A)
Simple random sampling
B)
Stratified sampling
C)
Cluster sampling
D)
Systematic random sampling
Answer Key
Testname: C1
29
Answer Key
Testname: C1
Answer Key
Testname: C1
Answer Key
Testname: C1