Deck 1: The Nature of Statistics

Question 1

Use the random number table in Appendix A to obtain the required list of random numbers.
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.

Answer 1

691, 3863, 3034, 978, 4584, 99, 362, 245, 1788, 4947, 471, 1562, 684, 2598

Question 2

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.

Answer 2

Answers will vary.

Question 3

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.

Answer 3

the sample was obtained from among
people who own a computer. That group is likely to include relatively wealthy
people who are more likely to favor a tax cut. Furthermore, the group includes those
who chose voluntarily to respond. People who respond voluntarily are likely to
have stronger opinions than the average voter.

Question 4

Define the terms population and sample.

Question 5

Describe the advantages and disadvantages of cluster sampling as compared with simple
random sampling.

Question 6

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.

Question 7

Provide an appropriate response.
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?

Question 8

In a designed experiment, explain the difference between the treatments and the factors.

Question 9

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?

Question 10

Fill in the following blanks: The two major types of statistics are ______________ statistics
and ___________ statistics.

Question 11

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?

Question 12

Explain the difference between an observational study and a designed experiment.

Question 13

Provide an appropriate response.
Which method of sampling is easier: simple random sampling or systematic random
sampling?

Question 14

Use the random number table in Appendix A to obtain the required list of random numbers.
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.

Question 15

Define probability sampling. Identify some advantages of probability sampling.

Question 16

Describe a double-blind experiment and explain why blinding is used. Define the term
"placebo effect" as part of the answer.

Question 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. 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?

Question 18

A store manager wishes to deter ether 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 int e 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?

Question 19

Provide an appropriate response.
Define the terms "stratified sampling", "systematic sampling" and "cluster sampling". Give
examples for each.

Question 20

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.

Question 21

Provide an appropriate response.
Define simple random sampling. Explain why this is important in design of experiments.

Question 22

A designed experiment is described. Identify the specified element of the experiment.
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.

A)Placebo, low dosage of drug, high dosage of drug
B)Diastolic blood pressure at start, diastolic blood pressure at end
C)Low dosage of drug, high dosage of drug
D)The experimental drug

Question 23

Provide an appropriate response.
Describe the steps involved when using stratified random sampling with proportional
allocation. What are the advantages of this sampling method?

Question 24

Provide an appropriate response.
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?

Question 25

Provide an appropriate response.
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?

A)Stratified sampling
B)Systematic sampling
C)Multistage sampling
D)Cluster sampling

Question 26

List all possible samples from the specified population.
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.

A)P,P P,V P,S P,T P,F V,V V,S V,T V,F S,S
B)S,T S,F T,P T,V T,S T,F F,P F,V F,S F,T
C)P,V P,S P,T P,F V,S V,T V,F S,T S,F T,F
D)P,V P,S P,T P,F V,P V,S V,T V,F S,P S,V

Question 27

Use the random number table in Appendix A to obtain the required list of random numbers.
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.

A)Systematic sampling
B)Cluster sampling
C)Stratified sampling
D)Attempted census

Question 28

List all possible samples from the specified population.
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.

A)Sample: the 74% who answered "yes"; population: all college students
B)Sample: the 50,000 selected college students; population: the 74% who answered "yes"
C)Sample: all college students; population: the 50,000 selected college students
D)Sample: the 50,000 selected college students; population: all college students

Question 29

List all possible samples from the specified population.
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.

Question 30

A designed experiment is described. Identify the specified element of the experiment.
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).

A)Large or small, dark or light, high pitch, normal pitch, or low pitch
B)Body type and mating call
C)Whether or not (yes or no)the female frogs approached a male dummy
D)Body size, body color, and mating call pitch

Question 31

Provide an appropriate response.
True or false? In simple random sampling, each possible sample is equally likely to be the one
obtained.

Question 32

A designed experiment is described. Identify the specified element of the experiment.
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.

A)Whether or not (yes or no)the female frogs approached a male dummy
B)Large and small; dark and light; call and no call
C)The four life-sized dummy male bullfrogs
D)Whether or not the male frogs were large and light-colored

Question 33

Provide an appropriate response.
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. Classify the study as either descriptive or inferential.

A)Descriptive
B)Inferential

Question 34

Identify the study as an observational study or a designed experiment.
A political pollster reports that his candidate has a 10% lead in the polls with 10% undecided.

A)Designed experiment
B)Observational study

Question 35

Identify the study as an observational study or a designed experiment.
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.

A)Designed experiment
B)Observational study

Question 36

Provide an appropriate response.
A statistics student's presentation of the results of her study included many charts, graphs, and tables. Identify the kind of statistical study conducted.

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.

Question 37

Use the random number table in Appendix A to obtain the required list of random numbers.
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.

Question 38

Identify the study as an observational study or a designed experiment.
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 7% of the subscribers respond to the questionnaire. Of the 7% who do respond, an average of
47% say that they will renew their subscription. This 7% who respond to the questionnaire are
Known as what?

A)The population
B)The sample

Question 39

Provide an appropriate response.
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.

A)Stratified sampling
B)Simple random sampling
C)Cluster sampling
D)Systematic random sampling

Question 40

Provide an appropriate response.
A newly-premiered play just ended that evening at a local theater. Theater management briefly interviews every eighth 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.

A)Stratified sampling
B)Multistage sampling
C)Systematic sampling
D)Cluster sampling

Question 41

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.

A)
B)
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)

Question 42

A designed experiment is described. Identify the specified element of the experiment.
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

A)Teaching method
B)Score on reading test
C)Method A, method B, method C
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.
D)Teacher

Question 43

Identify the study as an observational study or a designed experiment.
A doctor performs several diagnostic tests to determine the reason for a patient's illness.

A)Designed experiment
B)Observational study

Question 44

Deep CheckA designed experiment is described. Identify the specified element of the experiment.
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

A)Teaching method and teacher
B)Method A, method B, method C
C)
C)The 258 students participating in the study
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).

Question 45

Provide an appropriate response.
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.

A)Systematic sampling
B)Cluster sampling
C)Multistage sampling
D)Stratified sampling

Question 46

Identify the study as an observational study or a designed experiment.
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.

A)Designed experiment
B)Observational study

Question 47

Provide an appropriate response.
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 7
Boxes containing 50 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 10 cables chosen randomly within that
Box. What is the population?

A)350 cables
B)The one box that was chosen at random from the 7 boxes
C)The 10 cables chosen randomly for testing
D)The 7 boxes

Question 48

A designed experiment is described. Identify the specified element of the experiment.
A magazine publisher mails a survey to every subscriber asking about the quality of its subscription service. The total number of subscribers represents what?

A)The population
B)The sample

Question 49

A designed experiment is described. Identify the specified element of the experiment.
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.

A)Sample: the 100,000 selected adults; population: all adults
B)Sample: the 100,000 selected adults; population: the 45% of adults who drink at least 48 oz of water
C)Sample: all adults ; population: the 100,000 selected adults
D)Sample: the 45% of adults who drink at least 48 oz of water; population: all adults

Question 50

A designed experiment is described. Identify the specified element of the experiment.
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.

A)The eighteen different possible combinations of the two body sizes, three body colors, and three mating call pitches
B)The twelve different possible combinations of the three body sizes, two body colors, and two 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

Question 51

Provide an appropriate response.
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?

A)Multistage sampling
B)Stratified sampling
C)Cluster sampling
D)Systematic sampling

Question 52

A designed experiment is described. Identify the specified element of the experiment.
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.

A)The participants in the experiment
B)The dosage of the drug
C)Diastolic blood pressure
D)The experimental drug

Question 53

Provide an appropriate response.
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. Classify the study as either descriptive or inferential.

A)Descriptive
B)Inferential

Question 54

Identify the study as an observational study or a designed experiment.
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.

A)Designed experiment
B)Observational study

Question 55

Provide an appropriate response.
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?

A)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).
B)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.
C)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.
D)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.

Question 56

Identify the study as an observational study or a designed experiment.
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.

A)Designed experiment
B)Observational study

Question 57

Provide an appropriate response.
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.

A)Cluster sampling
B)Systematic random sampling
C)Stratified sampling
D)Simple random sampling

Question 58

Identify the study as an observational study or a designed experiment.
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.

A)Designed experiment
B)Observational study

Question 59

A designed experiment is described. Identify the specified element of the experiment.
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.

A)The participants in the experiment
B)The treatment received (placebo, low dosage, high dosage)
C)Change in diastolic blood pressure
D)The dosage of the drug

Question 60

A designed experiment is described. Identify the specified element of the experiment.
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

A)Teaching method and teacher
B)Juliana and method A, Juliana and method B, Juliana and method C, Felix and method A, Felix and method B, Felix and method C
C)Method A, method B, method C
C). The number of students participating in the study is 258. Students are randomly assigned to a teaching method and teacher. Identify the treatments.
D)Juliana, Felix, Sonia, and Helen

Question 61

A designed experiment is described. Identify the specified element of the experiment.
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).

A)The three different groups
B)The treatment (i.e., placebo, low dosage of drug, or high dosage of drug)
C)The participants in the experiment
D)The diastolic blood pressures of the participants

Question 62

A designed experiment is described. Identify the specified element of the experiment.
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.

A)There are three levels: body size, body color, and mating call pitch
B)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.
C)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.
D)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.

Question 63

List all possible samples from the specified population.

-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.

A) $$\begin{array} { l } \mathrm { A } , \mathrm { B } , \mathrm { C } , \mathrm { D } \quad \mathrm { A } , \mathrm { B } , \mathrm { C } , \mathrm { E } \quad \mathrm { A } , \mathrm { C } , \mathrm { D } , \mathrm { E } \quad \mathrm { A } , \mathrm { D } , \mathrm { E } , \mathrm { B } \quad \mathrm { B } , \mathrm { C } , \mathrm { D } , \mathrm { E } \quad \mathrm { B } , \mathrm { C } , \mathrm { E } , \mathrm { A } \quad \mathrm { B } , \mathrm { D } , \mathrm { E } , \mathrm { A } \\\mathrm { C } , \mathrm { A } , \mathrm { B } , \mathrm { D } \quad \mathrm { C } , \mathrm { E } , \mathrm { D } , \mathrm { B } \quad \mathrm { D } , \mathrm { A } , \mathrm { C } , \mathrm { E } \\\end{array}$$
B) $$\begin{array} { l } \mathrm { A } , \mathrm { B } , \mathrm { C } , \mathrm { D } \quad \mathrm { A } , \mathrm { B } , \mathrm { C } , \mathrm { E } \quad \mathrm { A } , \mathrm { C } , \mathrm { D } , \mathrm { E } \quad \mathrm { A } , \mathrm { D } , \mathrm { E } , \mathrm { B } \quad \mathrm { B } , \mathrm { C } , \mathrm { D } , \mathrm { E } \quad \mathrm { B } , \mathrm { C } , \mathrm { E } , \mathrm { A } \quad \mathrm { B } , \mathrm { D } , \mathrm { E } , \mathrm { A } \\\mathrm { C } , \mathrm { A } , \mathrm { B } , \mathrm { D } \quad \mathrm { C } , \mathrm { E } , \mathrm { D } , \mathrm { B } \quad \mathrm { D } , \mathrm { A } , \mathrm { C } , \mathrm { E } \\\end{array}$$ .
C) $$\text { A,B,C,D A,B,C,E A,C,D,E A,D,E,B }$$ .
D) A,B,C,D.

Question 64

Provide an appropriate response.
A magazine publisher mails a survey to every subscriber asking about the timeliness of its subscription service. The publisher finds that only 5% of the subscribers responded. This 5%
Represents what?

A)The population
B)The sample

Question 65

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. $$\mathrm { P } , \mathrm { V } \text { P,S P,T P,F V,S V,T V,F S,T S,F T,F }$$
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?

A) $\frac { 1 } { 20 }$
B) $\frac { 1 } { 10 }$
C) $\frac { 1 } { 5 }$
D) $\frac { 2 } { 5 }$

Question 66

Provide an appropriate response.
The table below shows the number of new AIDS cases in the U.S. in each of the years 1989-1994. Classify the study as either descriptive or inferential.

A)Descriptive
B)Inferential

Question 67

Provide an appropriate response.
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?

A)The total number of misspellings that Jackie finds in the latest proof of the history book
B)The latest proof of the history book
C)Finding misspellings in the latest proof of the history book
D)Every word in the latest proof of the history book

Question 68

Provide an appropriate response.
An employee at the local ice cream parlor asks three customers if they like chocolate ice cream. Identify the sample and population.

A)Sample: all customers; population: the 3 selected customers
B)Sample: the customers who like chocolate ice cream; population: all customers
C)Sample: the 3 selected customers; population: all customers
D)Sample: the 3 selected customers; population: the customers who like chocolate ice cream

Question 69

A designed experiment is described. Identify the specified element of the experiment.
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.

A)Diastolic blood pressure at the start, diastolic blood pressure at the end
B)High blood pressure, low blood pressure
C)The experimental drug
D)Placebo, low dosage, high dosage

Question 70

Provide an appropriate response.
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 50 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 10 cables chosen randomly within that
Box. What is the sample?

A)The 7 boxes
B)350 cables
C)The 10 cables chosen for testing
D)The one box that was chosen at random from the 7 boxes

Question 71

Provide an appropriate response.
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?

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.

Question 72

Provide an appropriate response.
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.

A)Systematic random sampling
B)Simple random sampling
C)Cluster sampling
D)Stratified sampling

Question 73

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. $$\begin{array} { l } \text { L,M,B L,M,D L,M,E L,M,J L,B,D L,B,E } \\\text { L,B,J L,D,E L,D,J L,E,J M,B,D M,B,E } \\\text { M,B,J M,D,E M,D,J M,E,J B,D,E B,D,J } \\\text { B,E,J D,E,J }\end{array}$$
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?

A) $\frac { 1 } { 2 }$
B) $\frac { 3 } { 20 }$
C) $\frac { 1 } { 3 }$
D) $\frac { 1 } { 20 }$

Question 74

Provide an appropriate response.
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?

A)Descriptive
B)Inferential

Question 75

A designed experiment is described. Identify the specified element of the experiment.
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.

A)The scientist
B)The female bullfrogs
C)The male bullfrogs
D)All of the frogs, male and female

Question 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. 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?

A) $\frac { 1 } { 6 }$
B) $\frac { 2 } { 15 }$
C) $\frac { 1 } { 15 }$
D) $\frac { 1 } { 3 }$

Question 77

Provide an appropriate response.
The table below shows the number of homicides in the U.S. in each of the years 1989-1993. Classify the study as either descriptive or inferential.

A)Descriptive
B)Inferential

Question 78

Provide an appropriate response.
George, a network engineer, ordered 700 CAT 5e Ethernet cables for use at his company's network. After receiving these cables, he decided to randomly test 210 of these cables before using them. He
Was alarmed to find out that 91% of these cables failed completely. He returned the entire lot to the
Manufacturer. When he tested the cables, what was George's sample?

A)210 cables
B)637 cables
C)191 cables
D)700 cables

Question 79

Identify the study as an observational study or a designed experiment.
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.

A)Designed experiment
B)Observational study

Question 80

Identify the study as an observational study or a designed experiment.
In a group of 500 men and women, those who smoked did worse on tests of reaction time than those who did not smoke.

A)Designed experiment
B)Observational study