Statistics Concepts and Controversies, 7th Edition.pdf

1、This page intentionally left blankStatisticsConcepts and ControversiesSenior Publisher:Craig BleyerPublisher:Ruth BaruthExecutive Marketing Manager:Jennifer SomervilleDevelopment Editors:Shona Burke,Anne Scanlan-RohrerSenior Media Editor:Roland CheyneyAssistant Editor:Brian TedescoEditorial Assistan

2、t:Katrina WilhelmMarketing Assistant:Eileen RothschildPhoto Editor:Ted SzczepanskiPhoto Researcher:Julie TesserText Designer:Vicki TomaselliCover Designer:Paula Jo SmithSenior Project Editor:Mary Louise ByrdIllustrations:ICC Macmillan Inc.,Mark ChickinelliProduction Manager:Paul W.RohloffComposition

3、:ICC Macmillan Inc.Printing and Binding:RR DonnellyMinitab is a registered trademark of Minitab,Inc.SPSS is a registered trademark of SPSS Inc.Library of Congress Control Number:2008932369ISBN-13:978-1-4292-2991-3ISBN-10:1-4292-2991-82009 by W.H.Freeman and Company.All rights reserved.Printed in the

4、 United States of AmericaFirst printingW.H.Freeman and Company41 Madison AvenueNew York,NY StatisticsConcepts and ControversiesSEVENTH EDITIONDavid S.MoorePurdue UniversityWilliam I.NotzThe Ohio State UniversityW.H.Freeman and CompanyNew YorkThis page intentionally left blank Brief ContentsPartIProd

5、ucing Data11Where Do Data Come From?32Samples,Good and Bad213What Do Samples Tell Us?354Sample Surveys in the Real World575Experiments,Good and Bad816Experiments in the Real World1017Data Ethics1238Measuring1439Do the Numbers Make Sense?165Part I Review181PartIIOrganizing Data19110 Graphs,Good and B

6、ad19311Displaying Distributions with Graphs21712 Describing Distributions with Numbers23913 Normal Distributions26514 Describing Relationships:Scatterplots and Correlation28715 Describing Relationships:Regression,Prediction,and Causation31116 The Consumer Price Index and Government Statistics339Part

7、 II Review359vviBrief ContentsPartIIIChance37317 Thinking about Chance37518 Probability Models39519 Simulation41120 The House Edge:Expected Values429Part III Review445PartIVInference45321 What Is a Confidence Interval?45522 What Is a Test of Significance?48123 Use and Abuse of Statistical Inference5

8、0524 Two-Way Tables and the Chi-Square Test521Part IV Review545This material is optional.ContentsTo the Teacher:Statistics as a Liberal DisciplinexiiiApplications IndexxxiPrelude:Making Sense of StatisticsxxviiStatistics and You:What Lies Ahead in This BookxxxiiiAbout the AuthorsxxxvPartIProducing D

9、ata11Where Do Data Come From?3Case Study 3Talking about data:Individuals and variables 4Observational studies 6Sample surveys 8Census 11Experiments 12Statistics in Summary 14Case StudyEvaluated 14Chapter 1 Exercises 15Exploring the Web 19Notes and Data Sources 192Samples,Good and Bad21Case Study 21H

10、ow to sample badly 21Simple randomsamples 23Can you trust a sample?28Statistics in Summary 29Case Study Evaluated 30Chapter 2 Exercises 30Exploring theWeb34 Notes and Data Sources 343What Do Samples Tell Us?35Case Study 35From sample to population 36Samplingvariability 37Margin of error and all that

11、 41Confidencestatements 43Sampling from large populations 45StatisticalControversies:Should Election Polls Be Banned?46Statistics inSummary 47Case Study Evaluated 48Chapter 3 Exercises 48Exploring the Web 54Notes and Data Sources 554Sample Surveys in the Real World57Case Study 57How sample surveys g

12、o wrong 58Samplingerrors 58Nonsampling errors 60Wording questions 63How to live with nonsampling errors 65Sample design in the realworld 65Questions to ask before you believe a poll 70Statistics inSummary 70Case Study Evaluated 71Chapter 4 Exercises 71Exploring the Web 78Notes and Data Sources 79vii

13、viiiContents5Experiments,Good and Bad81Case Study 81Talking about experiments 81How to experimentbadly 83Randomized comparative experiments 85The logic ofexperimental design 88Statistical significance 90How to livewith observational studies 91Statistics in Summary 93CaseStudy Evaluated 93Chapter 5 E

14、xercises 94Exploring the Web 99Notes and Data Sources 1006Experiments in the Real World101Case Study 101Equal treatment for all 101Double-blindexperiments 102Refusals,nonadherers,and dropouts 104Can we generalize?106Experimental design in the real world 108Matched pairs and block designs 110Statisti

15、cal Controversies:Is Itor Isnt It a Placebo?113Statistics in Summary 114Case StudyEvaluated 114Chapter 6 Exercises 115Exploring the Web 120Notes and Data Sources 1217Data Ethics123Case Study 123First principles 123Institutional reviewboards 125Informed consent 125Confidentiality 127Clinicaltrials 12

16、8Statistical Controversies:Hope for Sale?130Behavioral and social science experiments 132Statistics inSummary 134Case Study Evaluated 134Chapter 7 Exercises 135Exploring the Web 141Notes and Data Sources 1418Measuring143Case Study 143Measurement basics 143Know yourvariables 145Measurements valid and

17、 invalid 147StatisticalControversies:SAT Exams in College Admissions 150Measurements accurate and inaccurate 151Improving reliability,reducing bias 153Pity the poor psychologist 155Statistics inSummary 157Case Study Evaluated 158Chapter 8 Exercises 158Exploring the Web 163Notes and Data Sources 1639

18、Do the Numbers Make Sense?165Case Study 165What didnt they tell us?165Are the numbersconsistent with each other?167Are the numbers plausible?169Are the numbers too good to be true?169Is the arithmeticright?170Is there a hidden agenda?173Statistics inSummary 174Case Study Evaluated 174Chapter 9Exerci

19、ses 175Exploring the Web 179Notes and DataSources 180ContentsixPart I Review181Part I Summary 182Part I Review Exercises 183Part I Projects 188Notes and Data Sources 190PartIIOrganizing Data19110Graphs,Good and Bad193Case Study 193Data tables 193Pie charts and bar graphs 195Beware the pictogram 198C

20、hange over time:Line graphs 199Watch those scales!202Making good graphs 205Statisticsin Summary 207Case Study Evaluated 207Chapter 10Exercises 208Exploring the Web 216Notes and DataSources 21611Displaying Distributions with Graphs217Case Study 217Histograms 217Interpreting histograms 221Stemplots 22

21、6Statistics in Summary 229Case StudyEvaluated 229Chapter 11 Exercises 230Exploring the Web 237Notes and Data Sources 23812Describing Distributions with Numbers239Case Study 239Median and quartiles 240The five-numbersummary and boxplots 244Statistical Controversies:IncomeInequality 247Mean and standa

22、rd deviation 249Choosingnumerical descriptions 253Statistics in Summary 255Case StudyEvaluated 256Chapter 12 Exercises 256Exploring the Web 263Notes and Data Sources 26313Normal Distributions265Case Study 265Density curves 268The center and spread of adensity curve 269Normal distributions 270The 689

23、599.7rule 273Standard scores 275Percentiles of Normaldistributions277Statistics in Summary 278Case StudyEvaluated 279Chapter 13 Exercises 279Exploring theWeb 285Notes and Data Sources 28614Describing Relationships:Scatterplots and Correlation 287Case Study 287Scatterplots 288Interpreting scatterplot

24、s 292Correlation 295Understanding correlation 297Statistics inSummary 300Case Study Evaluated 300Chapter 14Exercises 301Exploring the Web 309Notes and DataSources 309This material is optional.xContents15Describing Relationships:Regression,Prediction,and Causation311Case Study 311Regression lines 312

25、Regression equations 314Understanding prediction 316Correlation and regression 318The question of causation 320Statistical Controversies:GunControl and Crime 324Evidence for causation 325Statisticsin Summary 326Case Study Evaluated 326Chapter 15Exercises 327Exploring the Web 336Notes and DataSources

26、 33616The Consumer Price Index and Government Statistics339Case Study 339Index numbers 340Fixed market basket priceindexes 341Using the CPI 342Understanding the CPI 346Statistical Controversies:Does the CPI Overstate Inflation?348The place of government statistics 348The question of socialstatistics

27、 350Statistics in Summary 351Case StudyEvaluated 352Chapter 16 Exercises 352Exploring theWeb 357Notes and Data Sources 358Part II Review359Part II Summary 360Part II Review Exercises 363Part II Projects 370Notes and Data Sources 372PartIIIChance37317Thinking about Chance375Case Study 375The idea of

28、probability 375The ancient historyof chance 378Myths about chance behavior 379Personalprobabilities 385Probability and risk 386Statistics inSummary 387Case Study Evaluated 388Chapter 17Exercises 389Exploring the Web 392Notes and DataSources 39318Probability Models395Case Study 395Probability models

29、395Probability rules 397Probability models for sampling 399Statistics in Summary 403Case Study Evaluated 404Chapter 18 Exercises 404Exploring the Web 409Notes and Data Sources 409Contentsxi19Simulation411Case Study 411Where do probabilities come from?412Simulationbasics 412Thinking about independenc

30、e 416More elaboratesimulations 418Statistics in Summary 421Case StudyEvaluated 421Chapter 19 Exercises 422Exploring the Web 427Notes and Data Sources 42820The House Edge:Expected Values429Case Study 429Expected values 429The law of largenumbers 433Thinking about expected values 434StatisticalControv

31、ersies:The State of Legalized Gambling 435Findingexpected values by simulation 435Statistics in Summary 437Case Study Evaluated 437Chapter 20 Exercises 438Exploringthe Web 443Notes and Data Sources 443Part III Review445Part III Summary 445Part III Review Exercises 447Part III Projects 451Notes and D

32、ata Sources 452PartIVInference45321What Is a Confidence Interval?455Case Study 455Estimating 456Estimating withconfidence 457Understanding confidence intervals 461More onconfidence intervals for a population proportion464The samplingdistribution of a sample mean467Confidence intervals for apopulatio

33、n mean469Statistics in Summary 471Case StudyEvaluated 472Chapter 21 Exercises 472Exploring theWeb 478Notes and Data Sources 47922What Is a Test of Significance?481Case Study 481The reasoning of statistical tests ofsignificance 482Hypotheses and P-values 485Statisticalsignificance 489Calculating P-va

34、lues489Tests for a populationmean491Statistics in Summary 495Case Study Evaluated 496Chapter 22 Exercises 496Exploring theWeb 502Notes and Data Sources 502This material is optional.xiiContents23Use and Abuse of Statistical Inference505Case Study 505Using inference wisely 505The woes ofsignificance t

35、ests 508The advantages of confidence intervals 511Significance at the 5%level isnt magical 512StatisticalControversies:Should Significance Tests Be Banned?513Beware ofsearching for significance 513Statistics in Summary 515CaseStudy Evaluated 515Chapter 23 Exercises 515Exploring theWeb 519Notes and D

36、ata Sources 51924Two-Way Tables and the Chi-Square Test521Case Study 521Two-way tables 522Inference for a two-waytable 523The chi-square test 526Using the chi-squaretest 530Simpsons paradox 533Statistics in Summary 536Case Study Evaluated 536Chapter 24 Exercises 536Exploringthe Web 542Notes and Data

37、 Sources 542Part IV Review545Part IV Summary 546Part IV Review Exercises 548Part IV Projects 554Notes and Data Sources 556Resolving the Controversy557Solutions to“Now Its Your Turn”Exercises562Answers to Odd-Numbered Exercises576Index597This material is optional.To the TeacherStatistics as a Liberal

38、 DisciplineStatistics:Concepts and Controversies(SCC)is a book on statistics asa liberal discipline,that is,as part of the general education of“non-mathematical”students.The book grew out of one of the authors ex-perience in developing and teaching a course for freshmen and sophomoresfrom Purdue Uni

39、versitys School of Liberal Arts.We are pleased that otherteachers have found SCC useful for unusually diverse audiences,extend-ing as far as students of philosophy and medicine.This seventh edition isa revision of the text,with several new features.It retains,however,thegoals of the original:to pres

40、ent statistics not as a technical tool but as partof the intellectual culture that educated people share.Statistics among the liberal artsStatistics has a widespread reputation as the least liberal of subjects.Whenstatistics is praised,it is most often for its usefulness.Health professionalsneed sta

41、tistics to read accounts of medical research;managers need statis-tics because efficient crunching of numbers will find its way to the bottomline;citizens need statistics to understand opinion polls and the ConsumerPrice Index.Because data and chance are omnipresent,our propagandaline goes,everyone

42、will find statistics useful,and perhaps even profitable.This is true.We would even argue that for most students the concep-tual and verbal approach in SCC is better preparation for future encoun-ters with statistical studies than the usual methods-oriented introduction.The joint curriculum committee

43、 of the American Statistical Associationand the Mathematical Association of America recommends that any firstcourse in statistics“emphasize the elements of statistical thinking”andfeature“more data and concepts,fewer recipes and derivations.”SCC doesthis,with the flavor appropriate to a liberal educ

44、ation:more concepts,morethinking,only simple data,fewer recipes,and no formal derivations.There is,however,another justification for learning about statisticalideas:statistics belongs among the liberal arts.A liberal education em-phasizes fundamental intellectual skills,that is,general methods of in

45、-quiry that apply in a wide variety of settings.The traditional liberal artspresent such methods:literary and historical studies,the political and so-cial analysis of human societies,the probing of nature by experimental sci-ence,the power of abstraction and deduction in mathematics.The case thatxii

46、ixivTo the Teacherstatistics belongs among the liberal arts rests on the fact that reasoningfrom uncertain empirical data is a similarly general intellectual method.Data and chance,the topics of this book,are pervasive aspects of our ex-perience.Though we employ the tools of mathematics to work with

47、 dataand chance,the mathematics implements ideas that are not strictly math-ematical.In fact,psychologists argue convincingly that mastering formalmathematics does little to improve our ability to reason effectively aboutdata and chance in everyday life.SCC is shaped,as far as the limitations of the

48、 authors and the intendedreaders allow,by the view that statistics is an independent and fundamen-tal intellectual method.The focus is on statistical thinking,on what othersmight call quantitative literacy or numeracy.The nature of this bookThere are books on statistical theory and books on statisti

49、cal methods.Thisis neither.It is a book on statistical ideas and statistical reasoning and ontheir relevance to public policy and to the human sciences from medicineto sociology.We have included many elementary graphical and numericaltechniques to give flesh to the ideas and muscle to the reasoning.

50、Studentslearn to think about data by working with data.We have not,however,allowed technique to dominate concepts.Our intention is to teach verballyrather than algebraically,to invite discussion and even argument ratherthan mere computation,though some computation remains essential.Thecoverageiscons