商务统计学知到智慧树章节测试课后答案2024年秋上海大学

商务统计学知到智慧树章节测试课后答案2024年秋上海大学绪论单元测试

PennyBauer,ChiefFinancialOfficerofHarrisonHaulage,suspectsirregularitiesinthepayrollsystem,andordersaninspectionof‘eachandeverypayrollvoucherissuedsince1January2005’.Fivepercentofthepayrollvoucherscontainedmaterialerrors.Thisisanexampleof________________.

A:descriptivestatisticsB:nominaldataC:nonparametricstatisticsD:inferentialstatistics

答案:descriptivestatistics

第一章单元测试

MichaelBayley,MarketingDirectorofUniPower’sElectricalDivision,isleadingastudytoidentifyandassesstherelativeimportanceofproductfeatures.MichaeldirectshisstafftodesignasurveyquestionnairefordistributiontoallofUniPower’s954customers.Forthisstudy,thesetof954customersisa________________.

A:statistic

B:population

C:sample

D:parameter

答案:population

ClaudiaTaylor,DirectorofGlobalIndustrialSalesinMelbourne,isconcernedbyadeterioratingsalestrend.Specifically,thenumberofcustomersisstableat1500buttheyarepurchasinglesseachyear.Sheordersherstafftosearchforcausesofthedownwardtrendbyselectingafocusgroupof40industrialcustomers.Forthisstudy,thesetof40industrialcustomersisa_______.

A:statistic

B:sample

C:parameter

D:population

答案:sample

Apoliticianwhoisrunningfortheofficeofpremierinastatewith3millionregisteredvoterscommissionsasurvey.Inthesurvey,53.6%ofthe5000registeredvotersinterviewedsaytheyplantovoteforhim.Thepopulationofinterestisthe

A:5000registeredvotersinterviewed.

B:46.4%of,or2320,votersinterviewedwhoplannottovoteforhim

C:3millionregisteredvotersinthestate.

D:53.6%of,or2680,votersinterviewedwhoplantovoteforhim

答案:3millionregisteredvotersinthestate.

SimonArnett,DirectorofHumanResources,isexploringthecausesofemployeeabsenteeismatBuderimBottlingduringthelastoperatingyear(1

January2005to31

December2005).Theaveragenumberofabsencesperemployee,calculatedfromthepersonneldataofallemployees,isa___________________.

A:parameter

B:sample

C:population

D:statistic

答案:parameter

Asummarymeasurethatiscomputedfromasampletodescribeacharacteristicofthepopulationiscalled

A:apopulation

B:aparameter

C:BothAandCarecorrect,sincetheyarethesame

D:astatistic

答案:astatistic

SimonArnett,DirectorofHumanResources,isexploringthecausesofemployeeabsenteeismatBuderimBottlingduringthelastoperatingyear(1

January2005to31

December2005).Personnelrecordsof50employeesareselectedforanalysis.(Theplantemploys250.)Forthisstudy,theaveragenumberdaysabsentforthese50

employeesisa________________.

A:population

B:sample

C:statistic

D:parameter

答案:statistic

Descriptivestatisticsdealswithmethodsof

A:summarisingdata

B:organisingdata.

C:presentingdatainaconvenientandinformativeway

D:doingalloftheabove

答案:doingalloftheabove

Whichofthefollowingstatementsisnottrue?

A:Inthelanguageofstatistics,thetermpopulationreferstoagroupofpeople

B:Oneformofdescriptivestatisticsusesgraphicaltechniques

C:Oneformofdescriptivestatisticsusesnumericaltechniques

D:Statisticalinferenceisusedtodrawconclusionsorinferencesaboutcharacteristicsofpopulationsbasedonsampledata

答案:Inthelanguageofstatistics,thetermpopulationreferstoagroupofpeople

Astudentachievesan82onthefirsttestinastatisticscourse.Fromthis,sheassumesthatheraverageattheendofthesemester(afterothertests)willbeabout82.Thisisanexampleof___________________.

A:nonparametricstatistics

B:inferentialstatistics

C:descriptivestatistics

D:wishfulthinking

答案:inferentialstatistics

Whichofthefollowingisnotthegoalofdescriptivestatistics?

A:Displayingaspectsofthecollecteddata

B:Estimatingcharacteristicsofthepopulation

C:Reportingnumericalfindings

D:Summarisingdata

答案:Estimatingcharacteristicsofthepopulation

第二章单元测试

Ifdataaregroupedintointervalsandthenumberofitemsineachgroupislisted,thiscouldbecalleda_______________.

A:ogive

B:stemandleafplot

C:frequencydistribution

D:histogram

答案:histogram

Iftheindividualclassfrequencyisdividedbythetotalfrequency,theresultisthe__________.

A:cumulativefrequency

B:relativefrequency

C:midpointfrequency

D:stemandleafplot

答案:relativefrequency

Acumulativefrequencypolygonisalsocalled_______________.

A:anogive

B:ahistogram

C:afrequencypolygon

D:astemandleafplot

答案:anogive

Thenumberofclassintervalsinafrequencydistributionisusuallybetween___________.

A:7and9

B:3and5

C:1and25

D:5and15

答案:5and15

Oneadvantageofastemandleafplotoverafrequencydistributionisthat__________.

A:theclassmidpointsareusedasthestem

B:theclassmidpointsareusedastheleaf

C:itcontainsmoreclassintervals

D:thevaluesoftheoriginaldataareretained

答案:thevaluesoftheoriginaldataareretained

Onerulethatmustalwaysbefollowedinconstructingfrequencydistributionsisthat________.

A:thenumberofintervalsmustbeanoddnumber

B:thenumberofclassesmustbelessthan10

C:thewidthofeachclassisequaltotherange

D:eachdatapointcanonlyfallintooneclass

答案:eachdatapointcanonlyfallintooneclass

Whichofthefollowingisbesttoshowthepercentageofatotalbudgetthatisspentoneachcategoryofitems?

A:piechart

B:stemandleafchart

C:ogive

D:histogram

答案:piechart

Acumulativefrequencydistributionwouldprovide_____________.

A:theproportionofthetotalfrequencieswhichfallintoeachclass

B:arunningtotalofthefrequenciesintheclasses

C:agraphofafrequencydistribution

D:averycloudypictureofthefrequencies

答案:arunningtotalofthefrequenciesintheclasses

Thenumberofphonecallsarrivingataswitchboardeachhourhasbeenrecordedandthefollowingfrequencydistributionhasbeendeveloped.

ClassIntervalFrequency20-under403040-under604560-under808080-under10045

Whatisthecumulativefrequencyofthethirdclass?

A:80

B:155

C:75

D:0.40

答案:155

Thenumberofphonecallsarrivingataswitchboardeachhourhasbeenrecordedandthefollowingfrequencydistributionhasbeendeveloped.

ClassIntervalFrequency20-under403040-under604560-under808080-under10045

Whatistheapproximaterangeofthenumberofphonecallsarrivingeachhour?

A:20B:80C:200D:100

答案:80

第三章单元测试

SimonArnett,DirectorofHumanResources,isexploringemployeeabsenteeismattheBuderimBottlingduringthelastoperatingyear.Asampleofsixpersonnelrecordsproducedthefollowingdata:0,2,4,7,2,9.Thevarianceofthenumberabsencesperemployeeis____________.

A:3.11B:11.6C:9.67D:3.41

答案:11.6JessicaSalas,ManagingDirectorofSalasProducts,isreviewingthewarrantypolicyforhercompany’snewmodelofcarbatteries.Lifetestsperformedonasampleof100batteriesindicated:(1)anaveragelifeof75months,(2)astandarddeviationof5months,and(3)batterylifeisapproximatelynormallydistributed.Approximately68%ofthebatterieswilllastbetween________________.

A:65and85months

B:60and90months

C:70and80months

D:55and95months

答案:70and80months

Theaveragestartingsalaryforgraduatesatauniversityis$25,000withastandarddeviationof$2000.AhistogramofthedatashowstheshapetobeveryerraticsoChebyshev’sTheoremshouldbeused.Howmanyofthegraduateswouldhaveastartingsalarybetween21,000and29,000?

A:atleast68%

B:atleast89%

C:atleast75%

D:atleast95%

答案:atleast75%

Thesamplestandarddeviationisfoundbytakingthesquarerootof_______.

A:thecoefficientofvariation

B:themeanabsolutedeviation

C:thesamplemean

D:thesamplevariance

答案:thesamplevariance

Thenumberofstandarddeviationsthatavalue(X)isaboveorbelowthemeanisthe_______.

A:interquartilerange

B:Zscore

C:absolutedeviation

D:coefficientofvariation

答案:Zscore

Inahistogram,theproportionofthetotalareathatmustbetotheleftofthemedianis（）

A:between0.25and0.60ifthedistributionissymmetricandunimodal

B:lessthan0.50ifthedistributionisskewedtotheleft

C:morethan0.50ifthedistributionisskewedtotheright

D:exactly0.50.

答案:exactly0.50.

WhichofthefollowingisNOTameasureofcentraltendency?

A:mean

B:variance

C:mode

D:median

答案:variance

Anothertermforaverageis____________.

A:mean

B:variance

C:median

D:mode

答案:mean

Ifthemeanofadistributionisgreaterthanthemedian,thenthedistributionis____________.

A:skewedtotheright

B:symmetricalaboutitsmean

C:notskewed

D:skewedtotheleft

答案:skewedtotheright

Themeanisnotaffectedbytheextremevalues.

A:对B:错

答案:错

第四章单元测试

Aprocessthatproducesoutcomesiscalled_______.

A:anevent

B:populationequivalent

C:aresult

D:anexperiment

答案:anexperiment

WhichofthefollowingisNOTalegitimateprobabilityvalue?

A:0.67

B:0.23

C:4/3

D:15/16

答案:4/3

Anoutcomeofanexperimentiscalled_______.

A:acomplement

B:anevent

C:apriorielements

D:aprobability

答案:anevent

Thelistofallelementaryeventsforanexperimentiscalled_______.

A:theexhaustivelist

B:thepopulationspace

C:thesamplespace

D:theeventunion

答案:thesamplespace

IfAandBaremutuallyexclusiveeventswithP(A)=0.70,thenP(B)：（）

A:cannotbelargerthan0.30

B:cantakeanyvaluebetween0and0.70

C:cannotbedeterminedfromtheinformationgiven

D:cantakeanyvaluebetween0and1

答案:cannotbelargerthan0.30

IfaneventisinsetXbutisnotinsetY,whichofthefollowingistrue?

A:itisinboththeunionandintersectionofXandYB:itisintheunionofXandY

C:itisintheintersectionofXandY

D:itisnotintheunionofXandY

答案:itisintheunionofXandY

Iftheoccurrenceofoneeventdoesnotaffecttheoccurrenceofanotherevent,thenthetwoeventsare_______.

A:complements

B:mutuallyexclusive

C:independent

D:elementaryevents

答案:independent

LetAbetheeventthatastudentisenrolledinanaccountingcourse,andletSbetheeventthatastudentisenrolledinastatisticscourse.Itisknownthat30%ofallstudentsareenrolledinanaccountingcourseand40%ofallstudentsareenrolledinstatistics.Includedinthesenumbersare15%whoareenrolledinbothstatisticsandaccounting.FindP(S).

A:0.55B:0.40C:0.30D:0.15

答案:0.40GivenP(A)=0.40,P(B)=0.50,P(A

B)=0.15.Whichofthefollowingistrue?

A:AandBarenotindependent

B:AandBareindependent

C:AandBaremutuallyexclusive

D:AandBarecollectivelyexhaustive

答案:AandBarenotindependent

MeaganDaviesmanagesaportfolioof200commonstocks.Herstaffclassifiedtheportfoliostocksby‘industrysector’and‘investmentobjective’.

InvestmentIndustrySector

ObjectiveElectronicsAirlinesHealthcareTotalGrowth1001040150Income20201050Total1203050200

WhichofthefollowingisNOTtrue?

A:ElectronicsandHealthcarearemutuallyexclusive.

B:GrowthandIncomearecomplementaryevents.

C:AirlinesandHealthcarearecollectivelyexhaustive.

D:ElectronicsandGrowtharedependent.

答案:AirlinesandHealthcarearecollectivelyexhaustive.

第五章单元测试

Variableswhichtakeonvaluesonlyatcertainpointsoveragivenintervalarecalled_______.

A:continuousrandomvariables

B:pointvariables

C:valuevariables

D:discreterandomvariables

答案:discreterandomvariables

Avariablethatcantakeonvaluesatanypointoveragivenintervaliscalled_______.

A:adiscreterandomvariable

B:acontinuousrandomvariable

C:apointvariable

D:avaluevariable

答案:acontinuousrandomvariable

Youareofferedaninvestmentopportunity.Itsoutcomesandprobabilitiesarepresentedinthefollowingtable.

XP(X)–$1000.40$0.20+$1000.40

Themeanofthisdistributionis_____________.

A:–$400

B:$0C:$400D:$200

答案:$0Youareofferedaninvestmentopportunity.Itsoutcomesandprobabilitiesarepresentedinthefollowingtable.

XP(X)–$1000.40$0.20+$1000.40

Thestandarddeviationofthisdistributionis_____________.

A:–$400

B:$800,000

C:$894

D:$663

答案:$894

Thelong-runaverageormeanofaPoissondistributionisusuallyreferredtoas_______.

A:a

B:s

C:m

D:l

答案:l

ThevarianceofaPoissondistributionisequalto_______.

A:l2

B:l/2

C:l

D:

答案:l

IfXisabinomialrandomwithn

=8andp

=0.6,whatistheprobabilitythatXislessthanorequalto2?

A:0.375B:0.009C:0.050D:0.041

答案:0.050IfXisabinomialrandomwithn

=8andp

=0.6,whatistheprobabilitythatXisgreaterthan2?

A:0.011B:0.124

C:0.991

D:0.950

答案:0.950

Twenty-fiveitemsaresampled.Eachofthesehasthesameprobabilityofbeingdefective.Theprobabilitythatexactly2ofthe25aredefectivecouldbestbefoundby_______.

A:usingthenormaldistribution

B:usingthebinomialdistribution

C:usingtheexponentialdistribution

D:usingthePoissondistribution

答案:usingthebinomialdistribution

Youareofferedaninvestmentopportunity.Itsoutcomesandprobabilitiesarepresentedinthefollowingtable.

XP(X)–$1000.40$0.20+$1000.40

Whichofthefollowingstatementsistrue?

A:Thisisabinomialdistribution.

B:Thisdistributionisskewedtotheleft.

C:Thisdistributionisskewedtotheright.

D:Thisdistributionissymmetric.

答案:Thisdistributionissymmetric.

第六章单元测试

Thenormaldistributionisanexampleof_______.

A:abimodaldistribution

B:acontinuousdistribution

C:adiscretedistribution

D:anexponentialdistribution

答案:acontinuousdistribution

Thetotalareaunderneathanynormalcurveis_______.

A:equaltothevariance

B:equalto1

C:equaltothemean

D:equaltothecoefficientofvariation

答案:equalto1

Theareatotheleftofthemeaninanynormaldistributionis_______.

A:equalto1

B:equaltothevariance

C:equalto0.5

D:equaltothemean

答案:equalto0.5

Foranynormaldistribution,anyvaluelessthanthemeanwouldhavea_______.

A:positivez-score

B:negativevariance

C:negativez-score

D:negativeprobabilityofoccurring

答案:negativez-score

Astandardisednormaldistributionhasthefollowingcharacteristics:

A:hemeanandvariancearebothequalto1

B:themeanisequalto0andthevarianceisequalto1

C:themeanandvariancearebothequalto0

D:themeanisequaltothevariance

答案:themeanisequalto0andthevarianceisequalto1

IfXisanormalrandomvariablewithmean80andstandarddeviation5,calculatethez-scoreifX=88.

A:-1.6

B:1.8C:-1.8

D:1.6

答案:1.6SupposeXisanormalrandomvariablewithmean60andstandarddeviation2.Az-scorewascalculatedforanumber,andthez-score

is3.4.Whatisx?

A:63.4B:56.6C:53.2D:66.8

答案:66.8LetXbeanormalrandomvariablewithmean20andstandarddeviation4.FindP(16<X<

22).

A:0.1498

B:0.0328

C:0.4672

D:0.5328

答案:0.5328

LetXbeanormalrandomvariablewithmean20andstandarddeviation4.The90thpercentileofXis____________.

A:22.698

B:20.000

C:26.579

D:25.126

答案:25.126

Az-score

isthenumberof__________thatavalueisfromthemean.

A:units

B:standarddeviations

C:miles

D:variances

答案:standarddeviations

第七章单元测试

Asageneralrule,thenormaldistributionisusedtoapproximatethesamplingdistributionofthesamplemeanonlyif

A:np

andn(1–p)arebothgreaterthan5

B:theunderlyingpopulationisnormal

C:thesamplemeaniscloseto0.50.

D:thesamplesizen

issufficientlylarge

答案:thesamplesizen

issufficientlylarge

TheeightemployeesoftheArtDepartmentandtheir‘yearsofexperience’arelistedinthefollowingtable.

EmployeeABCDEFGHExperience(years)1021115748

Ifasampleofthreeemployeesisselectedwithreplacement,thenumberofelementaryoutcomesinthesamplespaceis_______________.

A:512

B:64

C:56

D:336

答案:512

Asamplingdistributionisadistributionof_______________.

A:apopulationparameter,suchas,µ.

B:apopulationattribute,suchas,employee’sage.

C:excessprofitstoselectedshareholders.

D:asamplestatistic,suchas,

答案:asamplestatistic,suchas,Thestandarddeviationofasamplingdistributioniscommonlycalled_______.

A:thestandarderror.

B:theuniformspread.

C:statisticalleverage.

D:statisticalmargin.

答案:thestandarderror.

Thecentrallimittheoremstatesthatifn

islargeenough,thedistributionofthesamplemeansis_____________distributedregardlessoftheshapeofthepopulation.

A:nonrandomly

B:randomly

C:approximatelynormally

D:uniformly

答案:approximatelynormally

Accordingtothecentrallimittheorem,themeanofthesamplemeansforagivensizeofsampleisequalto_______.

A:thepopulationmean

B:thepopulationmeandividedbyn

C:thepopulationmeandividedbythesquarerootofn

D:zero

答案:thepopulationmean

Increasingthesamplesizecausesthestandarderrorofthemeanto________.

A:decreaseinvalue

B:destabiliseinvalue

C:seekmarketequilibrium

D:increaseinvalue

答案:decreaseinvalue

Increasingthesamplesizecausesthesamplingdistributionof

to________.

A:shifttotheleft

B:havelessdispersion

C:shifttotheright

D:havemoredispersion

答案:havelessdispersion

Supposeapopulationhasameanof90andastandarddeviationof28.Ifarandomsampleofsize49isdrawnfromthepopulation,theprobabilityofdrawingasamplewithameanofmorethan95is_______.

A:0.1056

B:0.4286

C:0.8944

D:0.3944

答案:0.1056

Suppose40%ofalluniversitystudentshaveacomputerathomeandasampleof64istaken.Whatistheprobabilitythatmorethan30ofthoseinthesamplehaveacomputerathome?

A:0.1314

B:0.3686

C:0.8686

D:0.6314

答案:0.1314

第八章单元测试

Whenarangeofvaluesisusedtoestimateapopulationparameter,itiscalled_______.

A:astatisticalparameter

B:anintervalestimate

C:apointestimate

D:arangeestimate

答案:anintervalestimate

CatherineCho,DirectorofMarketingResearchatVitalglowPtyLtd,isevaluatingconsumeracceptanceofanewtoothpastepackage.Herstaffreportthat17%ofarandomsampleof200Darwinhouseholdspreferthenewpackagetoallotherpackagedesigns.IfCatherineconcludesthat17%ofallhouseholdspreferthenewpackage,sheisusinga_______.

A:anintervalestimate

B:arangeestimate

C:apointestimate

D:astatisticalparameter

答案:apointestimate

Thez-value

associatedwithatwo-sided90%confidenceintervalis_______.

A:1.96

B:1.28

C:2.575

D:1.645

答案:1.645

Supposearandomsampleof36isselectedfromapopulationwithastandarddeviationof12.Ifthesamplemeanis98,the99%confidenceintervaltoestimatethepopulationmeanis_______.

A:94.08to101.92

B:93.34to102.66

C:97.35to98.65

D:92.85to103.15

答案:93.34to102.66

SamGates,MarketingDirectorofMansfieldMotors’ElectricalDivision,isleadingastudytoassesstherelativeimportanceofproductfeatures.Anitemonasurveyquestionnairedistributedto121Mansfieldcustomersaskedthemtoratetheimportanceof‘easeofmaintenance’onascaleof1to10(with1meaning‘notimportant’and10meaning‘highlyimportant’).Hisstaffassembledthefollowingstatistics.

EaseofMaintenanceMean7.5PopulationStandardDeviation1.1The90%confidenceintervalforthepopulationmeanratingof‘easeofmaintenance’is_____.

A:5.34to9.66

B:5.69to9.31

C:7.34to7.66

D:7.30to7.70

答案:7.34to7.66

Aresearcherwantstoestimatetheproportionofthepopulationwhichpossessagivencharacteristic.Arandomsampleofsize600istakenresultingin330itemswhichpossessthecharacteristic.Thepointestimateforthispopulationproportionis_______.

A:0.45

B:0.33

C:0.55

D:0.60

答案:0.55

Thet-distributionissimilartoanormaldistribution.Howeverthet-distributionis_______.

A:bimodal

B:discrete

C:notsymmetric

D:flatter

答案:flatter

Inordertofindvaluesinthet-

distributiontable,youmustconvertthesamplesizeorsizesto_______.

A:z-values

B:degreesoffreedom

C:populationsizes

D:studentvalues

答案:degreesoffreedom

Ifthedegreesoffreedominat-distributionbecomeverylarge,_______.

A:thesamplemeanapproacheszero

B:thepopulationsizemustbeverylarge

C:thesamplesizemustbeverysmall

D:thet-valuesandthez-valuesarealmostthesame

答案:thet-valuesandthez-valuesarealmostthesame

Infindingaconfidenceintervalforthepopulationmean,thepopulationstandarddeviationshouldbeusedifitisknown.Ifthepopulationstandarddeviationisnotknown,thenitshouldbeestimatedwith_______.

A:thesamplevariance

B:thesamplestandarddeviation

C:themean

D:therange

答案:thesamplestandarddeviation

第九章单元测试

Thefirststepintestingahypothesisistoestablish_______.

A:anindirecthypothesis

B:anullhypothesisandalternativehypothesis

C:apowerfunction

D:anotrejectancehypothesisandarejectionhypothesis

答案:anullhypothesisandalternativehypothesis

Considerthefollowingnullandalternativehypotheses.Ho:

m

<=7Ha:

m

>6Thesehypotheses_______________.

A:arenotcollectivelyexhaustive

B:arenotmutuallyexclusive

C:donotreferenceapopulationparameter

D:areestablishedcorrectly

答案:arenotmutuallyexclusive

Considerthefollowingnullandalternativehypotheses.

Ho:m>=

7

Ha:m

<6

Thesehypotheses_______________.

A:arenotmutuallyexclusive

B:areestablishedcorrectly

C:donotreferenceapopulationparameter

D:arenotcollectivelyexhaustive

答案:arenotcollectivelyexhaustive

Considerthefollowingnullandalternativehypotheses.Ho:

£

352

Ha:

>352

Thesehypotheses_______________.

A:arenotcollectivelyexhaustive

B:donotreferenceapopulationparameter

C:arenotmutuallyexclusive

D:areestablishedcorrectly

答案:donotreferenceapopulationparameter

Theregionofthedistributioninhypothesistestinginwhichthenullhypothesisisrejectediscalledthe_______.

A:rejectionregion

B:notrejectanceregion

C:nullregion

D:alternativeregion

答案:rejectionregion

Therejectionandnotrejectanceregionsaredividedbyapointcalledthe_______.

A:notrejectancevalue

B:rejectionvalue

C:criticalvalue

D:dividingpoint

答案:criticalvalue

TheprobabilityofcommittingaTypeIIerrorisrepresentedby_______.

A:a

/2

B:a

C:b

D:1–a

答案:b

JenniferCantu,CustomerServicesManageratTri-NationAutoInsurance,monitorstheclaimsprocessingtimeoftheclaimsdivision.Herstandardincludes‘ameanprocessingtimeof5daysorless’.Eachweek,herstaffchecksforcompliancebyanalysingarandomsampleof60claims.Jennifer’salternativehypothesisis________.

A:>5

B:n

=60

C:5

D:<5

答案:>5

Themanufacturersofadeodorantclaimthatthemeandryingtimeoftheirproductis,atmost,15minutes.Asampleconsistingof16cansoftheproductwasusedtotestthemanufacturer’sclaim.Theexperimentyieldedameandryingtimeof18minuteswithastandarddeviationof6minutes.Testtheclaimatthe0.05significancelevel.

A:Computedteststatistic=2andisgreaterthan1.753,sorejectH0:µ=15.

B:Computedteststatistic=2andisgreaterthan1.645,sorejectH0:µ≤15.

C:Computedteststatistic=2andisgreaterthan2.131,sorejectH0:µ≤15.

D:Computedteststatistic=2andisgreaterthan1.96,sorejectH0:µ≤15.

答案:Computedteststatistic=2andisgreaterthan1.753,sorejectH0:µ=15.

Whathappenstotherejectionregionifthelevelofsignificanceischangedfrom0.10to0.05?

A:itgetssmaller

B:itgetslarger

C:itdoesnotchange

答案:itgetssmaller

第十章单元测试

Restaurateur,DanielValentine,isevaluatingtwosites,PortDouglasandMissionBeach,forhisnextrestaurant.HewantstoprovethatPortDouglasresidents(population1)dineoutmoreoftenthanMissionBeachresidents(population2).Dennyplanstotestthishypothesisusingarandomsampleof81familiesfromeachtown.Hisnullhypothesisis__________.

A:s12

<s22

B:m1

≤m2

C:m1–m2>0

D:p1

–p2

=0

答案:m1

≤m2

Aresearcherwantstoestimatethedifferenceinthemeansoftwopopulations.Arandomsampleof36itemsfromthefirstpopulationresultsinasamplemeanof430.Arandomsampleof49itemsfromthesecondpopulationresultsinasamplemeanof460.Thepopulationstandarddeviationsare120forthefirstpopulationand140forthesecondpopulation.Fromthisinformation,apointestimateofthedifferenceofpopulationmeanscanbecalculatedas_______.

A:43B:-13

C:-30

D:46

答案:-30

Aresearcherwantstoestimatethedifferenceinthemeansoftwopopulations.Arandomsampleof36itemsfromthefirstpopulationresultsinasamplemeanof430.Arandomsampleof49itemsfromthesecondpopulationresultsinasamplemeanof460.Thepopulationstandarddeviationsare120forthefirstpopulationand140forthesecondpopulation.Fromthisinformation,a95%confidenceintervalforthedifferenceinpopulationmeansis_______.

A:–102.83to42.43

B:85.44to25.44

C:–95.90to35.90

D:–76.53to16.53

答案:85.44to25.44

Aresearcherisinterestedintestingtodetermineifthemeanofpopulationoneisgreaterthanthemeanofpopulationtwo.Thenullhypothesisisthatthereisnodifferenceinthepopulationmeans(i.e.thedifferenceiszero).Thealternativehypothesisisthatthereisadifference(i.e.thedifferenceisnotequaltozero).Herandomlyselectsasampleof9itemsfrompopulationoneresultinginameanof14.3andastandarddeviationof3.4.Herandomlyselectsasampleof14itemsfrompopulationtworesultinginameanof11.8andastandarddeviation2.9.Heisusinganalphavalueof.10toconductthistest.Assumingthatthepopulationsarenormallydistributed,thedegreesoffreedomforthisproblemare_______.

A:2B:22C:15D:23

答案:15Aresearcherwantstoconductabefore/afterstudyon11subjectstodetermineifatreatmentresultsinanydifferenceinscores.Thenullhypothesisisthattheaveragedifferenceiszerowhilethealternativehypothesisisthattheaveragedifferenceisnotzero.Scoresareobtainedonthesubjectsbothbeforeandafterthetreatment.Aftersubtractingtheafterscoresfromthebeforescores,theaveragedifferenceiscalculatedtobe–2.40withasamplestandarddeviationof1.21.Assumethatthedifferencesarenormallydistributedinthepopulation.Thedegreesoffreedomforthistestare_______.

A:20B:11C:10D:9

答案:10Aresearcherisperformingatwo-tailedrelatedsamples(matchedpairs)t-test.Atotalof12peopleareinthesample,andbeforeandaftermeasuresaretaken.Theobservedt-value

forthisis–1.84.Thelevelofsignificanceis0.05.Thecorrectdecisionisto_______.

A:rejectthenullhypothesis

B:donotrejectthenullhypothesis

C:takealargersample

D:usethez-tableinsteadofthet-table

答案:donotrejectthenullhypothesis

StefanIrwin,MarketingManageratClassicMerchandi