Chapter 1 - The Nature of Probability and Statistics
EXERCISE SET 1-1 11. This is a descriptive statistic since it
describes the weight loss for a specific
1. Statistics is the science of conducting group of subjects, i.e. , the teenagers at
studies to collect, organize, summarize, Boston University.
analyze, and draw conclusions from data.
12. This is a descriptive statistic since it is
2. A variable is a characteristic or attribute based on the results of a survey of 2739
that can assume different values. individuals. However, if an inference were
made to all pet owners, it would be an
3. In a census, the researchers collect data inferential statistic.
from all subjects in the population.
13. This is an inferential statistic since a
4. A population consists of all subjects generalization has been made about the
under study while a sample is a subgroup of population.
the population.
14. This is an inferential statistic since a
5. Descriptive statistics consists of the generalization was made about the
collection, organization, summarization, and population of all kindergartens in the state
presentation of data while inferential of Oregon.
statistics consists of generalizing from
15. This is an inferential statistic since a
samples to populations, performing
generalization was made about the
estimations and hypothesis testing,
population.
determining relationships among variables,
and making predictions.
16. This is a descriptive statistic since it
describes the results of a specific survey of
6. Probability is used in gambling,
1,507 subjects.
insurance, and weather forecasting.
17. This is an inferential statistic since it is
7. Samples are used more than populations
a generalization made from data obtained
both because populations are usually large
from a sample.
and because researchers are unable to use
every subject in the population. 18. Answers will vary.
8. A biased sample is a sample that is not 19. Answers will vary.
representative of the population.
EXERCISE SET 1-2
9. This is inferential because a
generalization is being made about the 1. Qualitative variables are variables that
population. can be placed in distinct categories
according to some characteristic or
10. This is inferential since a prediction is attribute and cannot be ranked; while
being made about the future. quantitative variables are numerical in
nature and can be ordered or counted.
Copyright © 2018 McGraw-Hill Education.
All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education
1
, Chapter 1 - The Nature of Probability and Statistics
2. Discrete variables assume values that can 29. Ratio 30. Ratio
be counted while continuous variables are
variables obtained by being measured. EXERCISE SET 1-3
Theoretically, continuous variables can
assume all values between any given two 1. Data can be collected by using telephone
values. surveys, mail questionnaire surveys, personal
interview surveys, by taking a look at records,
3. Continuous variables need to be rounded or by direct observation methods.
because of the limits of the measuring
2. Sampling error is the difference between a
device.
sample measure and a population measure.
Nonsampling error is the result of collecting
4. There are four types of measurement
data incorrectly or selecting a biased sample.
levels used in statistics: nominal, ordinal,
interval, and ratio levels of measurement. 3. Random numbers are used in sampling so
that every subject in the population has an
5. Qualitative 6. Qualitative
equal chance of being selected for a sample.
Random numbers can be generated by
7. Quantitative 8. Quantitative
computers or calculators; however, there are
9. Quantitative 10. Qualitative other ways of generating random numbers
such as using a random number table or
11. Discrete 12. Continuous rolling dice.
4. The four basic sampling methods are
13. Continuous 14. Discrete
random, systematic, stratified, and cluster
15. Discrete methods.
16. Continuous
5. The population could be all people in the
17. 23.5-24.5 feet
United States who earn over $200,000 per
annum. A sample could have been created by
18. 6.25-6.35 millimeters
selecting 500 people randomly from an
19. 142.5-143.5 miles accounting firm that prepares income taxes.
Answers will vary.
20. 19.625-19.635 tons
6. The population could be all prisons in the
free world. A sample of a specific number
21. 200.65-200.75 miles
could be selected by randomly choosing
prisons in the United States and prisons in
22. 18.5-19.5 quarts
other countries. Answers will vary.
23. Nominal 24. Interval
7. The population could be all households in
the United States. A sample could be selected
25. Ratio 26. Ratio
using 1000 households in the United States.
27. Ordinal 28. Nominal Answers will vary.
Copyright © 2018 McGraw-Hill Education.
All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education
2
,Solutions Manual for Elementary Statistics A Step By Step Approach 10e Allan Bluman (All Chapters, 100% Original Verified, A+ Grade)
Chapter 1 - The Nature of Probability and Statistics
8. The population could be all adults in the 3. One advantage of an observational study is
United States. A sample could be obtained that it can occur in a natural setting. In
by checking the blood levels of calcium. Of addition, researchers can look at past instances
course, the researcher must be aware of the of statistics and draw conclusions from these
privacy rights of the respondents. Answers situations. Another advantage is that the
will vary. researcher can use variables, such as drugs,
that he or she cannot manipulate.
9. The population could be all adults in the One disadvantage is that since the variable
United States who develop diabetes. The cannot be manipulated, a definite cause-and-
sample could be surveying patient records of effect situation cannot be shown. Another
these people to see if they have been taking disadvantage is that these studies can be
statins. Again, the privacy rights must be expensive and time-consuming. These studies
considered. Answers will vary. can also be influenced by confounding
variables. Finally, in these studies, the
10. The population could consist of all daily researcher sometimes needs to rely on data
temperatures in Boston since records were collected by others.
kept, and a sample could be obtained by
looking at weather report statistics. 4. One advantage of an experimental study is
that the researcher can decide how to select the
11. Systematic 12. Stratified
subjects and assign them to the specific
groups. The researcher can also control the
13. Random 14. Cluster
independent variable. One disadvantage of an
experimental study is that it may not occur in a
15. Cluster 16. Random
natural setting. Another one is called the
Hawthorne effect, and which is when the
EXERCISE SET 1-4
subject may change their natural behavior
1. In an observational study, the researcher because they realize that they are participating
observes what is happening and tries to in a research study.
draw conclusions based on the observations.
5. In an experimental study, the researcher has
In an experimental study, the researcher
control of the assignment of subjects to the
manipulates one of the variables and tries to
groups whereas in a quasi-experimental study,
determine how this influences the variables.
the researcher uses intact groups.
2. The three types of observational studies
6. An independent variable is the one being
are
manipulated by the researcher whereas the
a. Cross-sectional studies in which the data
dependent variable is the one being studied to
are collected at one point in time
identify the effects of the independent variable.
b. Retrospective studies in which the data
are collected from past records 7. In research studies, a treatment group
c. Longitudinal studies in which the data subject receives a specific treatment while
are collected over a period of time those in the control group do not receive a
treatment or are given a placebo.
Copyright © 2018 McGraw-Hill Education.
All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education
3
, Chapter 1 - The Nature of Probability and Statistics
8. The Hawthorne effect was the effect 14. Replication is done to determine if
discovered when researchers realized that results apply in different settings. For
the workers at the Hawthorne plant knew example, if the experiment was done with
that they were participating in a research college students, the researchers might
study and this fact actually changed replicate the experiment with adults or in
workers' behavior. another part of the country.
9. A confounding variable is one that can 15. Observational
influence the results of the research study
when no precautions were taken to 16. Observational
eliminate it from the study.
17. Experimental
10. Sometimes subjects respond
favorably when given a placebo rather 18. Observational
than the real treatment.
19. Independent variable - minutes
11. Blinding is used to help eliminate the exercising Dependent variable - catching a
placebo effect. Here the subjects are cold
given a sugar pill that looks like the real
medical pill. The subjects do not know 20. Independent variable - hugs and hand
which pill they are getting. When double holding
blinding occurs, neither the subjects nor Dependent variable - heart rate and blood
the researchers are told who gets the real pressure
treatment or the placebo.
21. Independent variable - happy face on
12. Randomization is confounding the check
variables since randomly assigning Dependent variable - amount of the tip
subjects to groups tends to "balance out"
the inconsistencies 22. Independent variable - marital status
(such as age, social class, etc.) that each Dependent variable - cause of death
of the subjects brings to the study.
23. Age, income, socioeconomic status.
13. In a completely randomized design, Answers will vary.
the subjects are assigned to the groups
randomly, whereas in a matched-pair 24. Age, intelligence, family ties. Answers
design, subjects are matched on some will vary.
variable. Then one subject is randomly
assigned to one group, and the other 25. Income, number of hours worked, type
subject is assigned to the other group. In of boss. Answers will vary.
both types of studies, the treatments can
be randomly assigned to the groups. 26. Climate, diet, medicine. Answers will
vary.
Copyright © 2018 McGraw-Hill Education.
All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education
4
EXERCISE SET 1-1 11. This is a descriptive statistic since it
describes the weight loss for a specific
1. Statistics is the science of conducting group of subjects, i.e. , the teenagers at
studies to collect, organize, summarize, Boston University.
analyze, and draw conclusions from data.
12. This is a descriptive statistic since it is
2. A variable is a characteristic or attribute based on the results of a survey of 2739
that can assume different values. individuals. However, if an inference were
made to all pet owners, it would be an
3. In a census, the researchers collect data inferential statistic.
from all subjects in the population.
13. This is an inferential statistic since a
4. A population consists of all subjects generalization has been made about the
under study while a sample is a subgroup of population.
the population.
14. This is an inferential statistic since a
5. Descriptive statistics consists of the generalization was made about the
collection, organization, summarization, and population of all kindergartens in the state
presentation of data while inferential of Oregon.
statistics consists of generalizing from
15. This is an inferential statistic since a
samples to populations, performing
generalization was made about the
estimations and hypothesis testing,
population.
determining relationships among variables,
and making predictions.
16. This is a descriptive statistic since it
describes the results of a specific survey of
6. Probability is used in gambling,
1,507 subjects.
insurance, and weather forecasting.
17. This is an inferential statistic since it is
7. Samples are used more than populations
a generalization made from data obtained
both because populations are usually large
from a sample.
and because researchers are unable to use
every subject in the population. 18. Answers will vary.
8. A biased sample is a sample that is not 19. Answers will vary.
representative of the population.
EXERCISE SET 1-2
9. This is inferential because a
generalization is being made about the 1. Qualitative variables are variables that
population. can be placed in distinct categories
according to some characteristic or
10. This is inferential since a prediction is attribute and cannot be ranked; while
being made about the future. quantitative variables are numerical in
nature and can be ordered or counted.
Copyright © 2018 McGraw-Hill Education.
All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education
1
, Chapter 1 - The Nature of Probability and Statistics
2. Discrete variables assume values that can 29. Ratio 30. Ratio
be counted while continuous variables are
variables obtained by being measured. EXERCISE SET 1-3
Theoretically, continuous variables can
assume all values between any given two 1. Data can be collected by using telephone
values. surveys, mail questionnaire surveys, personal
interview surveys, by taking a look at records,
3. Continuous variables need to be rounded or by direct observation methods.
because of the limits of the measuring
2. Sampling error is the difference between a
device.
sample measure and a population measure.
Nonsampling error is the result of collecting
4. There are four types of measurement
data incorrectly or selecting a biased sample.
levels used in statistics: nominal, ordinal,
interval, and ratio levels of measurement. 3. Random numbers are used in sampling so
that every subject in the population has an
5. Qualitative 6. Qualitative
equal chance of being selected for a sample.
Random numbers can be generated by
7. Quantitative 8. Quantitative
computers or calculators; however, there are
9. Quantitative 10. Qualitative other ways of generating random numbers
such as using a random number table or
11. Discrete 12. Continuous rolling dice.
4. The four basic sampling methods are
13. Continuous 14. Discrete
random, systematic, stratified, and cluster
15. Discrete methods.
16. Continuous
5. The population could be all people in the
17. 23.5-24.5 feet
United States who earn over $200,000 per
annum. A sample could have been created by
18. 6.25-6.35 millimeters
selecting 500 people randomly from an
19. 142.5-143.5 miles accounting firm that prepares income taxes.
Answers will vary.
20. 19.625-19.635 tons
6. The population could be all prisons in the
free world. A sample of a specific number
21. 200.65-200.75 miles
could be selected by randomly choosing
prisons in the United States and prisons in
22. 18.5-19.5 quarts
other countries. Answers will vary.
23. Nominal 24. Interval
7. The population could be all households in
the United States. A sample could be selected
25. Ratio 26. Ratio
using 1000 households in the United States.
27. Ordinal 28. Nominal Answers will vary.
Copyright © 2018 McGraw-Hill Education.
All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education
2
,Solutions Manual for Elementary Statistics A Step By Step Approach 10e Allan Bluman (All Chapters, 100% Original Verified, A+ Grade)
Chapter 1 - The Nature of Probability and Statistics
8. The population could be all adults in the 3. One advantage of an observational study is
United States. A sample could be obtained that it can occur in a natural setting. In
by checking the blood levels of calcium. Of addition, researchers can look at past instances
course, the researcher must be aware of the of statistics and draw conclusions from these
privacy rights of the respondents. Answers situations. Another advantage is that the
will vary. researcher can use variables, such as drugs,
that he or she cannot manipulate.
9. The population could be all adults in the One disadvantage is that since the variable
United States who develop diabetes. The cannot be manipulated, a definite cause-and-
sample could be surveying patient records of effect situation cannot be shown. Another
these people to see if they have been taking disadvantage is that these studies can be
statins. Again, the privacy rights must be expensive and time-consuming. These studies
considered. Answers will vary. can also be influenced by confounding
variables. Finally, in these studies, the
10. The population could consist of all daily researcher sometimes needs to rely on data
temperatures in Boston since records were collected by others.
kept, and a sample could be obtained by
looking at weather report statistics. 4. One advantage of an experimental study is
that the researcher can decide how to select the
11. Systematic 12. Stratified
subjects and assign them to the specific
groups. The researcher can also control the
13. Random 14. Cluster
independent variable. One disadvantage of an
experimental study is that it may not occur in a
15. Cluster 16. Random
natural setting. Another one is called the
Hawthorne effect, and which is when the
EXERCISE SET 1-4
subject may change their natural behavior
1. In an observational study, the researcher because they realize that they are participating
observes what is happening and tries to in a research study.
draw conclusions based on the observations.
5. In an experimental study, the researcher has
In an experimental study, the researcher
control of the assignment of subjects to the
manipulates one of the variables and tries to
groups whereas in a quasi-experimental study,
determine how this influences the variables.
the researcher uses intact groups.
2. The three types of observational studies
6. An independent variable is the one being
are
manipulated by the researcher whereas the
a. Cross-sectional studies in which the data
dependent variable is the one being studied to
are collected at one point in time
identify the effects of the independent variable.
b. Retrospective studies in which the data
are collected from past records 7. In research studies, a treatment group
c. Longitudinal studies in which the data subject receives a specific treatment while
are collected over a period of time those in the control group do not receive a
treatment or are given a placebo.
Copyright © 2018 McGraw-Hill Education.
All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education
3
, Chapter 1 - The Nature of Probability and Statistics
8. The Hawthorne effect was the effect 14. Replication is done to determine if
discovered when researchers realized that results apply in different settings. For
the workers at the Hawthorne plant knew example, if the experiment was done with
that they were participating in a research college students, the researchers might
study and this fact actually changed replicate the experiment with adults or in
workers' behavior. another part of the country.
9. A confounding variable is one that can 15. Observational
influence the results of the research study
when no precautions were taken to 16. Observational
eliminate it from the study.
17. Experimental
10. Sometimes subjects respond
favorably when given a placebo rather 18. Observational
than the real treatment.
19. Independent variable - minutes
11. Blinding is used to help eliminate the exercising Dependent variable - catching a
placebo effect. Here the subjects are cold
given a sugar pill that looks like the real
medical pill. The subjects do not know 20. Independent variable - hugs and hand
which pill they are getting. When double holding
blinding occurs, neither the subjects nor Dependent variable - heart rate and blood
the researchers are told who gets the real pressure
treatment or the placebo.
21. Independent variable - happy face on
12. Randomization is confounding the check
variables since randomly assigning Dependent variable - amount of the tip
subjects to groups tends to "balance out"
the inconsistencies 22. Independent variable - marital status
(such as age, social class, etc.) that each Dependent variable - cause of death
of the subjects brings to the study.
23. Age, income, socioeconomic status.
13. In a completely randomized design, Answers will vary.
the subjects are assigned to the groups
randomly, whereas in a matched-pair 24. Age, intelligence, family ties. Answers
design, subjects are matched on some will vary.
variable. Then one subject is randomly
assigned to one group, and the other 25. Income, number of hours worked, type
subject is assigned to the other group. In of boss. Answers will vary.
both types of studies, the treatments can
be randomly assigned to the groups. 26. Climate, diet, medicine. Answers will
vary.
Copyright © 2018 McGraw-Hill Education.
All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education
4
