SOLUTION MANUAL
ELEMENTARY STATISTICS
, INSTRUCTOR’S
SOLUTIONS
MANUAL
JAMES LAPP
ELEMENTARY STATISTICS
14TH EDITION
Mario F. Triola
,The Author And Publisher Of This Book Have Used Their Best Efforts In Preparing This Book. These Efforts
Include The Development, Research, And Testing Of The Theories And Programs To Determine Their Effectiveness.
The Author And Publisher Make No Warranty Of Any Kind, Expressed Or Implied, With Regard To These Programs
Or The Documentation Contained In This Book. The Author And Publisher Shall Not Be Liable In Any Event For
Incidental Or Consequential Damages In Connection With, Or Arising Out Of, The Furnishing, Performance, Or Use
Of These Programs.
Reproduced By Pearson From Electronic Files Supplied By The Author.
Copyright © 2018, 2014, 2010 Pearson Education, Inc.
Publishing As Pearson, 501 Boylston Street, Boston, MA 02116.
All Rights Reserved. No Part Of This Publication May Be Reproduced, Stored In A Retrieval System, Or
Transmitted, In Any Form Or By Any Means, Electronic, Mechanical, Photocopying, Recording, Or Otherwise,
Without The Prior Written Permission Of The Publisher. Printed In The United States Of America.
ISBN-13: 978-0-13-446420-6
ISBN-10: 0-13-446420-6
Www.Pearsonhighered.Com
, CONTENTS
Chapter 1: Introduction To Statistics
Section 1-1: Statistical And Critical Thinking .................................................................. 1
Section 1-2: Types Of Data ............................................................................................... 3
Section 1-3: Collecting Sample Data ................................................................................ 3
Chapter Quick Quiz........................................................................................................... 5
Review Exercises ..............................................................................................................5
Cumulative Review Exercises ........................................................................................... 6
Chapter 2: Exploring Data With Tables And Graphs
Section 2-1: Frequency Distributions For Organizing And Summarizing Data ............... 7
Section 2-2: Histograms .................................................................................................. 12
Section 2-3: Graphs That Enlighten And Graphs That Deceive ..................................... 14
Section 2-4: Scatterplots, Correlation, And Regression .................................................. 17
Chapter Quick Quiz......................................................................................................... 18
Review Exercises ............................................................................................................19
Cumulative Review Exercises ......................................................................................... 20
Chapter 3: Describing, Exploring, And Comparing Data
Section 3-1: Measures Of Center ....................................................................................21
Section 3-2: Measures Of Variation ................................................................................26
Section 3-3: Measures Of Relative Standing And Boxplots ........................................... 31
Chapter Quick Quiz......................................................................................................... 34
Review Exercises ............................................................................................................35
Cumulative Review Exercises ......................................................................................... 36
Chapter 4: Probability
Section 4-1: Basic Concepts Of Probability .................................................................... 37
Section 4-2: Addition Rule And Multiplication Rule ..................................................... 39
Section 4-3: Complements, Conditional Probability, And Bayes’ Theorem .................. 41
Section 4-4: Counting .....................................................................................................43
Chapter Quick Quiz......................................................................................................... 45
Review Exercises ............................................................................................................46
Cumulative Review Exercises ......................................................................................... 47
Chapter 5: Discrete Probability Distributions
Section 5-1: Probability Distributions .............................................................................49
Section 5-2: Binomial Probability Distributions. ............................................................ 51
Section 5-3: Poisson Probability Distributions ............................................................... 54
Chapter Quick Quiz......................................................................................................... 55
Review Exercises ............................................................................................................56
Cumulative Review Exercises ......................................................................................... 57
Chapter 6: Normal Probability Distributions
Section 6-1: The Standard Normal Distribution..............................................................59
, Section 6-2: Real Applications Of Normal Distributions................................................60
Section 6-3: Sampling Distributions And Estimators .....................................................64
Section 6-4: The Central Limit Theorem ........................................................................68
Section 6-5: Assessing Normality ...................................................................................71
Section 6-6: Normal As Approximation To Binomial ....................................................75
Chapter Quick Quiz.........................................................................................................77
Review Exercises ........................................................................................................... 78
Cumulative Review Exercises ........................................................................................ 79
Chapter 7: Estimating Parameters And Determining Sample Sizes
Section 7-1: Estimating A Population Proportion. ......................................................... 81
Section 7-2: Estimating A Population Mean. ................................................................. 85
Section 7-3: Estimating A Population Standard Deviation Or Variance ........................89
Section 7-4: Bootstrapping: Using Technology For Estimates .......................................92
Chapter Quick Quiz.........................................................................................................94
Review Exercises ........................................................................................................... 95
Cumulative Review Exercises ........................................................................................ 96
Chapter 8: Hypothesis Testing
Section 8-1: Basics Of Hypothesis Testing .....................................................................97
Section 8-2: Testing A Claim About A Proportion .........................................................99
Section 8-3: Testing A Claim About A Mean ...............................................................105
Section 8-4: Testing A Claim About A Standard Deviation Or Variance ................... 109
Chapter Quick Quiz.......................................................................................................112
Review Exercises ......................................................................................................... 112
Cumulative Review Exercises ...................................................................................... 113
Chapter 9: Chapter 9: Inferences From Two Samples
Section 9-1: Two Proportions....................................................................................... 115
Section 9-2: Two Means: Independent Samples ...........................................................124
Section 9-3: Two Dependent Samples (Matched Pairs)............................................... 130
Section 9-4: Two Variances Or Standard Deviations ...................................................134
Chapter Quick Quiz.......................................................................................................136
Review Exercises ......................................................................................................... 137
Cumulative Review Exercises ...................................................................................... 138
Chapter 10: Correlation And Regression
Section 10-1: Correlation ..............................................................................................141
Section 10-2: Regression ...............................................................................................148
Section 10-3: Prediction Intervals And Variation .........................................................157
Section 10-4: Multiple Regression. ...............................................................................159
Section 10-5: Nonlinear Regression ..............................................................................161
Chapter Quick Quiz.......................................................................................................165
Review Exercises ......................................................................................................... 165
Cumulative Review Exercises ...................................................................................... 166
Chapter 11: Goodness-Of-Fit And Contingency Tables
Section 11-1: Goodness-Of-Fit .....................................................................................169
, Section 11-2: Contingency Tables ................................................................................173
Chapter Quick Quiz.......................................................................................................177
Review Exercises ......................................................................................................... 178
Cumulative Review Exercises ...................................................................................... 179
Chapter 12: Analysis Of Variance
Section 12-1: One-Way ANOVA .................................................................................181
Section 12-2: Two-Way ANOVA .................................................................................183
Chapter Quick Quiz.......................................................................................................184
Review Exercises ......................................................................................................... 185
Cumulative Review Exercises ...................................................................................... 186
Chapter 13: Nonparametric Tests
Section 13-2: Sign Test .................................................................................................189
Section 13-3: Wilcoxon Signed-Ranks Test For Matched Pairs ...................................190
Section 13-4: Wilcoxon Rank-Sum Test For Two Independent Samples ....................192
Section 13-5: Kruskal-Wallis Test For Three Or More Samples ..................................195
Section 13-6: Rank Correlation .....................................................................................196
Section 13-7: Runs Test For Randomness ................................................................... 198
Chapter Quick Quiz.......................................................................................................199
Review Exercises ......................................................................................................... 200
Cumulative Review Exercises ...................................................................................... 201
Chapter 14: Statistical Process Control
Section 14-1: Control Charts For Variation And Mean ................................................203
Section 14-2: Control Charts For Attributes .................................................................205
Chapter Quick Quiz.......................................................................................................210
Review Exercises ......................................................................................................... 210
Cumulative Review Exercises ...................................................................................... 212
, Chapter 1: Introduction To Statistics 1
Chapter 1: Introduction To Statistics
Section 1-1: Statistical And Critical Thinking
1. The Respondents Are A Voluntary Response Sample Or A Self-Selected Sample. Because Those With
Strong Interests In The Topic Are More Likely To Respond, It Is Very Possible That Their Responses
Do Not Reflect The Opinions Or Behavior Of The General Population.
2. A. The Sample Consists Of The 1046 Adults Who Were Surveyed. The Population Consists Of All Adults.
B. When Asked, Respondents Might Be Inclined To Avoid The Shame Of The Unhealthy Habit Of Not
Washing Their Hands, So The Reported Rate Of 70% Might Well Be Much Higher Than It Is In
Reality. It Is Generally Better To Observe Or Measure Human Behavior Than To Ask Subjects
About It.
3. Statistical Significance Is Indicated When Methods Of Statistics Are Used To Reach A Conclusion That
A Treatment Is Effective, But Common Sense Might Suggest That The Treatment Does Not Make
Enough Of A Difference To Justify Its Use Or To Be Practical. Yes, It Is Possible For A Study To Have
Statistical Significance, But Not Practical Significance.
4. No. Correlation Does Not Imply Causation. The Example Illustrates A Correlation That Is Clearly Not The
Result Of Any Interaction Or Cause Effect Relationship Between Deaths In Swimming Pools And Power
Generated From Nuclear Power Plants.
5. Yes, There Does Appear To Be A Potential To Create A Bias.
6. No, There Does Not Appear To Be A Potential To Create A Bias.
7. No, There Does Not Appear To Be A Potential To Create A Bias.
8. Yes, There Does Appear To Be A Potential To Create A Bias.
9. The Sample Is A Voluntary Response Sample And Has Strong Potential To Be Flawed.
10. The Samples Are Voluntary Response Samples And Have Potential For Being Flawed, But This
Approach Might Be Necessary Due To Ethical Considerations Involved In Randomly Selecting Subjects
And Somehow Imposing Treatments On Them.
11. The Sampling Method Appears To Be Sound.
12. The Sampling Method Appears To Be Sound.
13. With Only A 1% Chance Of Getting Such Results With A Program That Has No Effect, The Program
Appears To Have Statistical Significance. Also, Because The Average Loss Of 22 Pounds Does Seem
Substantial, The Program Appears To Also Have Practical Significance.
14. Because There Is A 0.3% Chance Of Getting Such Results By Chance, The Increase In Scores Does Appear
To Have Statistical Significance. The Typical Increase Of 5 Points Suggests That The Course Does Have
Practical Significance. The Course Does Appear To Be Successful.
15. Because There Is A 19% Chance Of Getting That Many Girls By Chance, The Method Appears To Lack
Statistical Significance. The Result Of 1020 Girls In 2000 Births (51% Girls) Is Above The
Approximately 50% Rate Expected By Chance, But It Does Not Appear To Be High Enough To Have
Practical Significance. Not Many Couples Would Bother With A Procedure That Raises The Likelihood
Of A Girl From 50% To 51%.
16. Because There Is A 25% Chance Of Getting Such Results With A Program That Has No Effect, The
Program Does Not Appear To Have Statistical Significance. Because The Average Increase Is Only 3 IQ
Points, The Program Does Not Appear To Have Practical Significance.
17. Yes. Each Column Of 8 AM And 12 AM Temperatures Is Recorded From The Same Subject, So Each
Pair Is Matched.
18. No. The Source Is From University Researchers Who Do Not Appear To Gain From Distorting The Data.
19. The Data Can Be Used To Address The Issue Of Whether There Is A Correlation Between Body
Temperatures At 8 AM And At 12 AM. Also, The Data Can Be Used To Determine Whether There Are
Differences Between Body Temperatures At 8 AM And At 12 AM.
20. Because The Differences Could Easily Occur By Chance (With A 64% Chance), The Differences Do Not
Appear To Have Statistical Significance.
21. No. The White Blood Cell Counts Measure A Different Quantity Than The Red Blood Cell Counts,
So Their Differences Are Meaningless.
,Copyright © 2018 Pearson Education, Inc.
,2 Elementary Statistics, 14th Edition
22. The Issue That Can Be Addressed Is Whether There Is A Correlation, Or Association, Between White
Blood Cell Counts And Red Blood Cell Counts.
23. No. The National Center For Health Statistics Has No Reason To Collect Or Present The Data In A
Way That Is Biased.
24. No. Correlation Does Not Imply Causation, So A Statistical Correlation Between White Blood Cell
Counts And Red Blood Cell Counts Should Not Be Used To Conclude That Higher White Blood Cell
Counts Are The Cause Of Higher Red Blood Cell Counts.
25. It Is Questionable That The Sponsor Is The Idaho Potato Commission And The Favorite Vegetable Is Potatoes.
26. The Sample Is A Voluntary Response Sample, So There Is A Good Chance That The Results Do Not
Reflect The Larger Population Of People Who Have A Water Preference.
27. The Correlation, Or Association, Between Two Variables Does Not Mean That One Of The Variables Is
The Cause Of The Other. Correlation Does Not Imply Causation. Clearly, Sour Cream Consumption Is
Not Directly Related In Any Way To Motorcycle Fatalities.
28. The Sponsor Of The Poll Is An Electronic Cigarette Maker, So The Sponsor Does Have An Interest In
The Poll Results. The Source Is Questionable.
29. A. 700 Adults
B. 55%
30. A. 253.31 Subjects
b. No. Because The Result Is A Count Of People Among The 347 Who Were Surveyed, The Result
Must Be A Whole Number.
c. 253 Subjects
d. 32%
31. A. 559.2 Respondents
b. No. Because The Result Is A Count Of Respondents Among The 1165 Engaged Or Married Women
Who Were Surveyed, The Result Must Be A Whole Number.
c. 559 Respondents
d. 8%
32. A. 293.17 Women
b. No. Because The Result Is A Count Of Women Among The 1543 Who Were Surveyed, The Result
Must Be A Whole Number.
c. 293 Women
d. 15%
e. Interpretations Of A ―Typical‖ Week And What It Means To ―Kick Back And Relax‖ Might Vary
Considerably By Different Survey Respondents. The Survey Might Be Improved By Asking About
Behavior Within ―The Past Seven Days‖ Instead Of A ―Typical‖ Week. Instead Of ―Kick Back And
Relax,‖ Respondents Might Be Surveyed About Specific Behavior, Such As Reading, Taking A Nap,
Watching Television, Listening To Music, Or Going For A Walk.
33. Because A Reduction Of 100% Would Eliminate All Of The Size, It Is Not Possible To Reduce The Size
By 100% Or More.
34. In An Editorial Criticizing The Statement, The New York Times Correctly Interpreted The 100%
Improvement To Mean That No Baggage Is Being Lost, Which Was Not True.
35. Because A Reduction Of 100% Would Eliminate All Plaque, It Is Not Possible To Reduce It By More Than 100%.
36. If One Subgroup Receives A 4% Raise And Another Subgroup Receives A 4% Raise, The Combined
Group Will Receive A 4% Raise, Not An 8% Raise. The Percentages Should Not Be Added In This
Case.
37. The Wording Of The Question Is Biased And Tends To Encourage Negative Responses. The Sample Size
Of 20 Is Too Small. Survey Respondents Are Self-Selected Instead Of Being Randomly Selected By The
Newspaper. If 20 Readers Respond, The Percentages Should Be Multiples Of 5, So 87% And 13% Are
Not Possible Results.
38. All Percentages Of Success Should Be Multiples Of 5. The Given Percentages Cannot Be Correct.
, Chapter 1: Introduction To Statistics 3
Section 1-2: Types Of Data
1. The Population Consists Of All Adults In The United States, And The Sample Is The 2276 Adults
Who Were Surveyed. Because The Value Of 33% Refers To The Sample, It Is A Statistic.
2. A. Quantitative C. Categorical
B. Categorical D. Quantitative
3. Only Part (A) Describes Discrete
Data.
4. A. The Sample Is The 1020 Adults Who Were Surveyed. The Population Is All Adults In The United States.
b. Statistic
c. Ratio
d. Discrete
5. Statistic 17. Discrete
6. Statistic 18. Continuous
7. Parameter 19. Continuous
8. Parameter 20. Discrete
9. Statistic 21. Ordinal
10. Statistic 22. Nominal
11. Parameter 23. Nominal
12. Parameter 24. Ratio
13. Continuous 25. Interval
14. Continuous 26. Ordinal
15. Discrete 27. Ordinal
16. Discrete 28. Interval
29. The Numbers Are Not Counts Or Measures Of Anything. They Are At The Nominal Level Of
Measurement, And It Makes No Sense To Compute The Average (Mean) Of Them.
30. The Digits Are Not Counts Or Measures Of Anything. They Are At The Nominal Level Of
Measurement And It Makes No Sense To Calculate Their Average (Mean).
31. The Temperatures Are At The Interval Level Of Measurement. Because There Is No Natural Starting Point With
0∘ F Representing ―No Heat,‖ Ratios Such As ―Twice‖ Make No Sense, So It Is Wrong To Say That It Is
Twice As Warm At The Author’s Home As It Is In Auckland, New Zealand.
32. The Ranks Are At The Ordinal Level Of Measurement. Differences Between The Universities Cannot Be
Determined, So There Is No Way To Know Whether The Difference Between Princeton And Harvard Is
The Same As The Difference Between Yale And Columbia.
33. A. Continuous, Because The Number Of Possible Values Is Infinite And Not Countable.
b. Discrete, Because The Number Of Possible Values Is Finite.
c. Discrete, Because The Number Of Possible Values Is Finite.
d. Discrete, Because The Number Of Possible Values Is Infinite And Countable.
Section 1-3: Collecting Sample Data
1. The Study Is An Experiment Because Subjects Were Given Treatments.
2. The Subjects In The Study Did Not Know Whether They Were Taking A Placebo Or The Paracetamol
Medication, And Those Who Administered The Pills Also Did Not Know.
3. The Group Sample Sizes Of 547, 550, And 546 Are All Large So That The Researchers Could See The
Effects Of The Paracetamol Treatment.
4. The Sample Appears To Be A Convenience Sample. Given That The Subjects Were Randomly Assigned
To The Three Different Treatment Groups, It Appears That The Results Of The Study Are Good Because
They Are Not Likely To Be Distorted From Bias, But We Should Investigate The Sample Groups To
Ensure That They Are Not Fundamentally Different From The Population.
ELEMENTARY STATISTICS
, INSTRUCTOR’S
SOLUTIONS
MANUAL
JAMES LAPP
ELEMENTARY STATISTICS
14TH EDITION
Mario F. Triola
,The Author And Publisher Of This Book Have Used Their Best Efforts In Preparing This Book. These Efforts
Include The Development, Research, And Testing Of The Theories And Programs To Determine Their Effectiveness.
The Author And Publisher Make No Warranty Of Any Kind, Expressed Or Implied, With Regard To These Programs
Or The Documentation Contained In This Book. The Author And Publisher Shall Not Be Liable In Any Event For
Incidental Or Consequential Damages In Connection With, Or Arising Out Of, The Furnishing, Performance, Or Use
Of These Programs.
Reproduced By Pearson From Electronic Files Supplied By The Author.
Copyright © 2018, 2014, 2010 Pearson Education, Inc.
Publishing As Pearson, 501 Boylston Street, Boston, MA 02116.
All Rights Reserved. No Part Of This Publication May Be Reproduced, Stored In A Retrieval System, Or
Transmitted, In Any Form Or By Any Means, Electronic, Mechanical, Photocopying, Recording, Or Otherwise,
Without The Prior Written Permission Of The Publisher. Printed In The United States Of America.
ISBN-13: 978-0-13-446420-6
ISBN-10: 0-13-446420-6
Www.Pearsonhighered.Com
, CONTENTS
Chapter 1: Introduction To Statistics
Section 1-1: Statistical And Critical Thinking .................................................................. 1
Section 1-2: Types Of Data ............................................................................................... 3
Section 1-3: Collecting Sample Data ................................................................................ 3
Chapter Quick Quiz........................................................................................................... 5
Review Exercises ..............................................................................................................5
Cumulative Review Exercises ........................................................................................... 6
Chapter 2: Exploring Data With Tables And Graphs
Section 2-1: Frequency Distributions For Organizing And Summarizing Data ............... 7
Section 2-2: Histograms .................................................................................................. 12
Section 2-3: Graphs That Enlighten And Graphs That Deceive ..................................... 14
Section 2-4: Scatterplots, Correlation, And Regression .................................................. 17
Chapter Quick Quiz......................................................................................................... 18
Review Exercises ............................................................................................................19
Cumulative Review Exercises ......................................................................................... 20
Chapter 3: Describing, Exploring, And Comparing Data
Section 3-1: Measures Of Center ....................................................................................21
Section 3-2: Measures Of Variation ................................................................................26
Section 3-3: Measures Of Relative Standing And Boxplots ........................................... 31
Chapter Quick Quiz......................................................................................................... 34
Review Exercises ............................................................................................................35
Cumulative Review Exercises ......................................................................................... 36
Chapter 4: Probability
Section 4-1: Basic Concepts Of Probability .................................................................... 37
Section 4-2: Addition Rule And Multiplication Rule ..................................................... 39
Section 4-3: Complements, Conditional Probability, And Bayes’ Theorem .................. 41
Section 4-4: Counting .....................................................................................................43
Chapter Quick Quiz......................................................................................................... 45
Review Exercises ............................................................................................................46
Cumulative Review Exercises ......................................................................................... 47
Chapter 5: Discrete Probability Distributions
Section 5-1: Probability Distributions .............................................................................49
Section 5-2: Binomial Probability Distributions. ............................................................ 51
Section 5-3: Poisson Probability Distributions ............................................................... 54
Chapter Quick Quiz......................................................................................................... 55
Review Exercises ............................................................................................................56
Cumulative Review Exercises ......................................................................................... 57
Chapter 6: Normal Probability Distributions
Section 6-1: The Standard Normal Distribution..............................................................59
, Section 6-2: Real Applications Of Normal Distributions................................................60
Section 6-3: Sampling Distributions And Estimators .....................................................64
Section 6-4: The Central Limit Theorem ........................................................................68
Section 6-5: Assessing Normality ...................................................................................71
Section 6-6: Normal As Approximation To Binomial ....................................................75
Chapter Quick Quiz.........................................................................................................77
Review Exercises ........................................................................................................... 78
Cumulative Review Exercises ........................................................................................ 79
Chapter 7: Estimating Parameters And Determining Sample Sizes
Section 7-1: Estimating A Population Proportion. ......................................................... 81
Section 7-2: Estimating A Population Mean. ................................................................. 85
Section 7-3: Estimating A Population Standard Deviation Or Variance ........................89
Section 7-4: Bootstrapping: Using Technology For Estimates .......................................92
Chapter Quick Quiz.........................................................................................................94
Review Exercises ........................................................................................................... 95
Cumulative Review Exercises ........................................................................................ 96
Chapter 8: Hypothesis Testing
Section 8-1: Basics Of Hypothesis Testing .....................................................................97
Section 8-2: Testing A Claim About A Proportion .........................................................99
Section 8-3: Testing A Claim About A Mean ...............................................................105
Section 8-4: Testing A Claim About A Standard Deviation Or Variance ................... 109
Chapter Quick Quiz.......................................................................................................112
Review Exercises ......................................................................................................... 112
Cumulative Review Exercises ...................................................................................... 113
Chapter 9: Chapter 9: Inferences From Two Samples
Section 9-1: Two Proportions....................................................................................... 115
Section 9-2: Two Means: Independent Samples ...........................................................124
Section 9-3: Two Dependent Samples (Matched Pairs)............................................... 130
Section 9-4: Two Variances Or Standard Deviations ...................................................134
Chapter Quick Quiz.......................................................................................................136
Review Exercises ......................................................................................................... 137
Cumulative Review Exercises ...................................................................................... 138
Chapter 10: Correlation And Regression
Section 10-1: Correlation ..............................................................................................141
Section 10-2: Regression ...............................................................................................148
Section 10-3: Prediction Intervals And Variation .........................................................157
Section 10-4: Multiple Regression. ...............................................................................159
Section 10-5: Nonlinear Regression ..............................................................................161
Chapter Quick Quiz.......................................................................................................165
Review Exercises ......................................................................................................... 165
Cumulative Review Exercises ...................................................................................... 166
Chapter 11: Goodness-Of-Fit And Contingency Tables
Section 11-1: Goodness-Of-Fit .....................................................................................169
, Section 11-2: Contingency Tables ................................................................................173
Chapter Quick Quiz.......................................................................................................177
Review Exercises ......................................................................................................... 178
Cumulative Review Exercises ...................................................................................... 179
Chapter 12: Analysis Of Variance
Section 12-1: One-Way ANOVA .................................................................................181
Section 12-2: Two-Way ANOVA .................................................................................183
Chapter Quick Quiz.......................................................................................................184
Review Exercises ......................................................................................................... 185
Cumulative Review Exercises ...................................................................................... 186
Chapter 13: Nonparametric Tests
Section 13-2: Sign Test .................................................................................................189
Section 13-3: Wilcoxon Signed-Ranks Test For Matched Pairs ...................................190
Section 13-4: Wilcoxon Rank-Sum Test For Two Independent Samples ....................192
Section 13-5: Kruskal-Wallis Test For Three Or More Samples ..................................195
Section 13-6: Rank Correlation .....................................................................................196
Section 13-7: Runs Test For Randomness ................................................................... 198
Chapter Quick Quiz.......................................................................................................199
Review Exercises ......................................................................................................... 200
Cumulative Review Exercises ...................................................................................... 201
Chapter 14: Statistical Process Control
Section 14-1: Control Charts For Variation And Mean ................................................203
Section 14-2: Control Charts For Attributes .................................................................205
Chapter Quick Quiz.......................................................................................................210
Review Exercises ......................................................................................................... 210
Cumulative Review Exercises ...................................................................................... 212
, Chapter 1: Introduction To Statistics 1
Chapter 1: Introduction To Statistics
Section 1-1: Statistical And Critical Thinking
1. The Respondents Are A Voluntary Response Sample Or A Self-Selected Sample. Because Those With
Strong Interests In The Topic Are More Likely To Respond, It Is Very Possible That Their Responses
Do Not Reflect The Opinions Or Behavior Of The General Population.
2. A. The Sample Consists Of The 1046 Adults Who Were Surveyed. The Population Consists Of All Adults.
B. When Asked, Respondents Might Be Inclined To Avoid The Shame Of The Unhealthy Habit Of Not
Washing Their Hands, So The Reported Rate Of 70% Might Well Be Much Higher Than It Is In
Reality. It Is Generally Better To Observe Or Measure Human Behavior Than To Ask Subjects
About It.
3. Statistical Significance Is Indicated When Methods Of Statistics Are Used To Reach A Conclusion That
A Treatment Is Effective, But Common Sense Might Suggest That The Treatment Does Not Make
Enough Of A Difference To Justify Its Use Or To Be Practical. Yes, It Is Possible For A Study To Have
Statistical Significance, But Not Practical Significance.
4. No. Correlation Does Not Imply Causation. The Example Illustrates A Correlation That Is Clearly Not The
Result Of Any Interaction Or Cause Effect Relationship Between Deaths In Swimming Pools And Power
Generated From Nuclear Power Plants.
5. Yes, There Does Appear To Be A Potential To Create A Bias.
6. No, There Does Not Appear To Be A Potential To Create A Bias.
7. No, There Does Not Appear To Be A Potential To Create A Bias.
8. Yes, There Does Appear To Be A Potential To Create A Bias.
9. The Sample Is A Voluntary Response Sample And Has Strong Potential To Be Flawed.
10. The Samples Are Voluntary Response Samples And Have Potential For Being Flawed, But This
Approach Might Be Necessary Due To Ethical Considerations Involved In Randomly Selecting Subjects
And Somehow Imposing Treatments On Them.
11. The Sampling Method Appears To Be Sound.
12. The Sampling Method Appears To Be Sound.
13. With Only A 1% Chance Of Getting Such Results With A Program That Has No Effect, The Program
Appears To Have Statistical Significance. Also, Because The Average Loss Of 22 Pounds Does Seem
Substantial, The Program Appears To Also Have Practical Significance.
14. Because There Is A 0.3% Chance Of Getting Such Results By Chance, The Increase In Scores Does Appear
To Have Statistical Significance. The Typical Increase Of 5 Points Suggests That The Course Does Have
Practical Significance. The Course Does Appear To Be Successful.
15. Because There Is A 19% Chance Of Getting That Many Girls By Chance, The Method Appears To Lack
Statistical Significance. The Result Of 1020 Girls In 2000 Births (51% Girls) Is Above The
Approximately 50% Rate Expected By Chance, But It Does Not Appear To Be High Enough To Have
Practical Significance. Not Many Couples Would Bother With A Procedure That Raises The Likelihood
Of A Girl From 50% To 51%.
16. Because There Is A 25% Chance Of Getting Such Results With A Program That Has No Effect, The
Program Does Not Appear To Have Statistical Significance. Because The Average Increase Is Only 3 IQ
Points, The Program Does Not Appear To Have Practical Significance.
17. Yes. Each Column Of 8 AM And 12 AM Temperatures Is Recorded From The Same Subject, So Each
Pair Is Matched.
18. No. The Source Is From University Researchers Who Do Not Appear To Gain From Distorting The Data.
19. The Data Can Be Used To Address The Issue Of Whether There Is A Correlation Between Body
Temperatures At 8 AM And At 12 AM. Also, The Data Can Be Used To Determine Whether There Are
Differences Between Body Temperatures At 8 AM And At 12 AM.
20. Because The Differences Could Easily Occur By Chance (With A 64% Chance), The Differences Do Not
Appear To Have Statistical Significance.
21. No. The White Blood Cell Counts Measure A Different Quantity Than The Red Blood Cell Counts,
So Their Differences Are Meaningless.
,Copyright © 2018 Pearson Education, Inc.
,2 Elementary Statistics, 14th Edition
22. The Issue That Can Be Addressed Is Whether There Is A Correlation, Or Association, Between White
Blood Cell Counts And Red Blood Cell Counts.
23. No. The National Center For Health Statistics Has No Reason To Collect Or Present The Data In A
Way That Is Biased.
24. No. Correlation Does Not Imply Causation, So A Statistical Correlation Between White Blood Cell
Counts And Red Blood Cell Counts Should Not Be Used To Conclude That Higher White Blood Cell
Counts Are The Cause Of Higher Red Blood Cell Counts.
25. It Is Questionable That The Sponsor Is The Idaho Potato Commission And The Favorite Vegetable Is Potatoes.
26. The Sample Is A Voluntary Response Sample, So There Is A Good Chance That The Results Do Not
Reflect The Larger Population Of People Who Have A Water Preference.
27. The Correlation, Or Association, Between Two Variables Does Not Mean That One Of The Variables Is
The Cause Of The Other. Correlation Does Not Imply Causation. Clearly, Sour Cream Consumption Is
Not Directly Related In Any Way To Motorcycle Fatalities.
28. The Sponsor Of The Poll Is An Electronic Cigarette Maker, So The Sponsor Does Have An Interest In
The Poll Results. The Source Is Questionable.
29. A. 700 Adults
B. 55%
30. A. 253.31 Subjects
b. No. Because The Result Is A Count Of People Among The 347 Who Were Surveyed, The Result
Must Be A Whole Number.
c. 253 Subjects
d. 32%
31. A. 559.2 Respondents
b. No. Because The Result Is A Count Of Respondents Among The 1165 Engaged Or Married Women
Who Were Surveyed, The Result Must Be A Whole Number.
c. 559 Respondents
d. 8%
32. A. 293.17 Women
b. No. Because The Result Is A Count Of Women Among The 1543 Who Were Surveyed, The Result
Must Be A Whole Number.
c. 293 Women
d. 15%
e. Interpretations Of A ―Typical‖ Week And What It Means To ―Kick Back And Relax‖ Might Vary
Considerably By Different Survey Respondents. The Survey Might Be Improved By Asking About
Behavior Within ―The Past Seven Days‖ Instead Of A ―Typical‖ Week. Instead Of ―Kick Back And
Relax,‖ Respondents Might Be Surveyed About Specific Behavior, Such As Reading, Taking A Nap,
Watching Television, Listening To Music, Or Going For A Walk.
33. Because A Reduction Of 100% Would Eliminate All Of The Size, It Is Not Possible To Reduce The Size
By 100% Or More.
34. In An Editorial Criticizing The Statement, The New York Times Correctly Interpreted The 100%
Improvement To Mean That No Baggage Is Being Lost, Which Was Not True.
35. Because A Reduction Of 100% Would Eliminate All Plaque, It Is Not Possible To Reduce It By More Than 100%.
36. If One Subgroup Receives A 4% Raise And Another Subgroup Receives A 4% Raise, The Combined
Group Will Receive A 4% Raise, Not An 8% Raise. The Percentages Should Not Be Added In This
Case.
37. The Wording Of The Question Is Biased And Tends To Encourage Negative Responses. The Sample Size
Of 20 Is Too Small. Survey Respondents Are Self-Selected Instead Of Being Randomly Selected By The
Newspaper. If 20 Readers Respond, The Percentages Should Be Multiples Of 5, So 87% And 13% Are
Not Possible Results.
38. All Percentages Of Success Should Be Multiples Of 5. The Given Percentages Cannot Be Correct.
, Chapter 1: Introduction To Statistics 3
Section 1-2: Types Of Data
1. The Population Consists Of All Adults In The United States, And The Sample Is The 2276 Adults
Who Were Surveyed. Because The Value Of 33% Refers To The Sample, It Is A Statistic.
2. A. Quantitative C. Categorical
B. Categorical D. Quantitative
3. Only Part (A) Describes Discrete
Data.
4. A. The Sample Is The 1020 Adults Who Were Surveyed. The Population Is All Adults In The United States.
b. Statistic
c. Ratio
d. Discrete
5. Statistic 17. Discrete
6. Statistic 18. Continuous
7. Parameter 19. Continuous
8. Parameter 20. Discrete
9. Statistic 21. Ordinal
10. Statistic 22. Nominal
11. Parameter 23. Nominal
12. Parameter 24. Ratio
13. Continuous 25. Interval
14. Continuous 26. Ordinal
15. Discrete 27. Ordinal
16. Discrete 28. Interval
29. The Numbers Are Not Counts Or Measures Of Anything. They Are At The Nominal Level Of
Measurement, And It Makes No Sense To Compute The Average (Mean) Of Them.
30. The Digits Are Not Counts Or Measures Of Anything. They Are At The Nominal Level Of
Measurement And It Makes No Sense To Calculate Their Average (Mean).
31. The Temperatures Are At The Interval Level Of Measurement. Because There Is No Natural Starting Point With
0∘ F Representing ―No Heat,‖ Ratios Such As ―Twice‖ Make No Sense, So It Is Wrong To Say That It Is
Twice As Warm At The Author’s Home As It Is In Auckland, New Zealand.
32. The Ranks Are At The Ordinal Level Of Measurement. Differences Between The Universities Cannot Be
Determined, So There Is No Way To Know Whether The Difference Between Princeton And Harvard Is
The Same As The Difference Between Yale And Columbia.
33. A. Continuous, Because The Number Of Possible Values Is Infinite And Not Countable.
b. Discrete, Because The Number Of Possible Values Is Finite.
c. Discrete, Because The Number Of Possible Values Is Finite.
d. Discrete, Because The Number Of Possible Values Is Infinite And Countable.
Section 1-3: Collecting Sample Data
1. The Study Is An Experiment Because Subjects Were Given Treatments.
2. The Subjects In The Study Did Not Know Whether They Were Taking A Placebo Or The Paracetamol
Medication, And Those Who Administered The Pills Also Did Not Know.
3. The Group Sample Sizes Of 547, 550, And 546 Are All Large So That The Researchers Could See The
Effects Of The Paracetamol Treatment.
4. The Sample Appears To Be A Convenience Sample. Given That The Subjects Were Randomly Assigned
To The Three Different Treatment Groups, It Appears That The Results Of The Study Are Good Because
They Are Not Likely To Be Distorted From Bias, But We Should Investigate The Sample Groups To
Ensure That They Are Not Fundamentally Different From The Population.
