统计学

BusinessStatisticsReviewSectionsTrueorFalseF1AcontinuousvariablemaytakeonanyvaluewithinitsrelevantrangeeventhoughtheMeasurementdevicemaynotbepreciseenoughtorecordit.F2AMarinedrillinstructorrecordedthetimeinwhicheachof11recruitscompletedanobstaclecoursebothbeforeandafterbasictraining.Totestwhetheranyimprovementoccurred,theinstructorwoulduseat-distributionwith11degreesoffreedom.T3Asamplingdistributionisadistributionforastatistic.T4Atestforthedifferencebetweentwoproportionscanbeperformedusingthechi-squaredistribution.F5Asthesizeofthesampleisincreased,thestandarddeviationofthesamplingdistributionofthesamplemeanforanormallydistributedpopulationwillstaythesame.T6Determiningacollegestudent’sacademicmajorwouldbeanexampleofmeasurementonanominalscaleofmeasurement.T7Foragivenlevelofsignificance,ifthesamplesizeisincreased,thepowerofthetestwillincrease.F8Foragivenlevelofsignificance,ifthesamplesizeisincreased,theprobabilityofcommittingaTypeIerrorwillincrease.T9Foralltwo-sampletests,thesamplesizesmustbeequalinthe2groups.T10Histogramsareusedfornumericaldatawhilebarchartsaresuitableforcategoricaldata.F11IfP(A)=0.4andP(B)=0.6,thenAandBmustbecollectivelyexhaustive.T12Ifthepopulationdistributionissymmetric,thesamplingdistributionofthemeancanbeapproximatedbythenormaldistributionifthesamplescontain15observations.F13Inachi-squaretest,itispossiblefortheobservedfrequenciestobefractionsordecimalvalues.T14Inaone-factorANOVAanalysis,theamongsumofsquaresandwithinsumofsquaresmustadduptothetotalsumofsquares.F15Informinga90%confidenceintervalforapopulationmeanfromasamplesizeof22,thenumberofdegreesoffreedomfromthetdistributionequals22.F16Intestingthedifferencebetweentwoproportionsusingthenormaldistribution,wemayuseeitheraone-tailedChi-squaretestortwo-tailedZtest.17Ogivesareplottedatthemidpointsoftheclassgroupings.T18Otherthingsbeingequal,astheconfidencelevelforaconfidenceintervalincreases,thewidthoftheintervalincreases.T19Repeatedmeasurementsfromthesameindividualsisanexampleofdatacollectedfrom2relatedpopulations.F20Studentgrades(AtoF)areanexampleofcontinuousnumericaldata.F21Theanalysisofvariance(ANOVA)testshypothesesaboutthepopulationvariance.F22Theanswertothequestion“Whatisyourfavoritecolor?”isanexampleofanordinalscaledvariable.F23Thecoefficientofvariationmeasuresvariabilityinadatasetrelativetothesizeofthearithmeticmean.F24TheFdistributionissymmetric.T25Theinterquartilerangeisameasureofvariationordispersioninasetofdata.F26Themedianofthevalues3.4,4.7,1.9,7.6,and6.5is1.9.F27Themedianofthevalues3.4,4.7,1.9,7.6,and6.5is4.05.F28Thenumberofcustomersarrivingatadepartmentstoreina5-minuteperiodhasabinomialdistribution.F29Theprobabilitythatastandardnormalrandomvariable,Z,fallsbetween–2.00and–0.44is0.6472.T30Theprobabilitythatastandardnormalrandomvariable,Z,isbetween1.50and2.10isthesameastheprobabilityZisbetween–2.10and–1.50.T31Thesmalleristhep-value,thestrongeristheevidenceagainstthenullhypothesis.T32Thesumofcumulativefrequenciesinadistributionalwaysequals1.F33Thesumofrelativefrequenciesinadistributionalwaysequals1.F34WhenAandBaremutuallyexclusive,P(AorB)canbefoundbyaddingP(A)andP(B).T35WhentheFtestisusedforANOVA,therejectionregionisalwaysintherighttail.T36Aresearcheriscuriousabouttheeffectofsleeponstudents’testperformances.Hechooses60studentsandgiveseach2tests:onegivenafter2hours’sleepandoneafter8hours’sleep.Thetesttheresearchershouldusewouldbearelatedsamplestest.T37Asampleistheportionoftheuniversethatisselectedforanalysis.F38InaPoissondistribution,themeanandvarianceareequal.T39Thelargeristhep-value,themorelikelyoneistorejectthenullhypothesis.T40Thenumberofcustomersarrivingatadepartmentstoreina5-minuteperiodhasaPoissondistribution.ChoiceATheprocessofusingsamplestatisticstodrawconclusionsabouttruepopulationparametersiscalled(A)statisticalinference.(B)thescientificmethod.(C)sampling.(D)descriptivestatistics.DThosemethodsinvolvingthecollection,presentation,andcharacterizationofasetofdatainordertoproperlydescribethevariousfeaturesofthatsetofdataarecalled(A)statisticalinference.(B)thescientificmethod.(C)sampling.(D)descriptivestatistics.CThecollectionandsummarizationofthesocioeconomicandphysicalcharacteristicsoftheemployeesofaparticularfirmisanexampleof(A)inferentialstatistics.(B)descriptivestatistics.(C)aparameter.(D)astatistic.DTheestimationofthepopulationaveragefamilyexpenditureonfoodbasedonthesampleaverageexpenditureof1,000familiesisanexampleof(A)inferentialstatistics.(B)descriptivestatistics.(C)aparameter.(D)astatistic.BTheuniverseortotalityofitemsorthingsunderconsiderationiscalled(A)asample.(B)apopulation.(C)aparameter.(D)astatistic.ATheportionoftheuniversethathasbeenselectedforanalysisiscalled(A)asample.(B)aframe.(C)aparameter.(D)astatistic.BAsummarymeasurethatiscomputedtodescribeacharacteristicofanentirepopulationiscalled(A)acensus.(B)aparameter.(C)astatistic.(D)thescientificmethod.CAsummarymeasurethatiscomputedtodescribeacharacteristicfromonlyasampleofthepopulationiscalled(A)aparameter.(B)acensus.(C)astatistic.(D)thescientificmethod.DWhichoft