《Businessstatistic》复习参考复习课程

1、BusinessStatistic中国人民大学出版社英文版第五版chapter18复习参考Parti名词解释1、Statisticsisamethodofextractingusefulinformationfromasetofnumericaldatainordertomakeamoreeffectiveandinformeddecision.2、DescriptiveStatistics:Thesearestatisticalmethodsoforganizing,summarizingandpresentingnumericaldatainconvenientformssuchasgra

2、phs,chartsandtables.3、Inferentialstatisticsisdefinedasstatisticalmethodsusedfordrawingconclusionsaboutapopulationbasedonsamples.4、Primarydataisobtainedfirsthand.5、Secondarydataalreadyexistsorhasbeenpreviouslycollectedsuchascompanyaccounts,orsalesfigures.6、Mean:Thearithmeticaverageandthemostcommonmea

3、sureofaaaaaaacentraltendency.Allvaluesareincludedincomputingthemean.AsetofdatahasauniquemeanThemeanisaffectedbyunusuallylargeorsmalldatapoints(outliers/extremevalues).7、Mode:Themostfrequentdata,ordatacorrespondingtothehighestfrequency.Modeisnotaffectedbyextremevalues.Theremaynotbeamode.Theremaybesev

4、eralmodes.Usedforeithernumericalorcategoricaldata.8、Medianisthevaluethatsplitsarankedsetofdataintotwoequalparts.Medianisnotaffectedbyextremelylargeorsmallvaluesandisthereforeavaluablemeasureofcentraltendencywhensuchvaluesoccur.9、StandardDeviation:Ameasureofthevariationofdatafromthemean.Themostcommon

5、lyusedmeasureofvariation.Representedbythesymbols.Showshowthedataisdistributedaroundthemean.10、Probabilityisthechanceofanoccurrenceofanevent.Probabilityofaneventalwaysliesbetween0and1.Thesumoftheprobabilitiesofeverypossibleoutcomeoreventis1.TheprobabilityofthecomplementAisP(A)enby111、PropertiesofNorm

6、aldistribution:Continuousrandomvariable.Be-shaped&symmetrical.Mean,median,modeareequalAreaunderthecurveis1.12、TheCentralLimitedTheorem:Ifthepopulationfollowednormaldistribution,thesamplingdistributionofmeanisfollowednormaldistribution.Ifthepopulationdonotfollowednormaldistribution,butthesamplesizeis

7、largerthan30,thesamplingdistributionofmeanisfollowednormaldistribution.Part2选择题Topic1-IntroductiontoBusinessStatistics&DataCollectionQ1.Theuniverseortotalityofitemsorthingsunderconsiderationiscalled:a. asample.b. apopulation.c. aparameter.d. noneoftheabove.Q2.Thosemethodsinvolvingthecollection,prese

8、ntation,andcharacterizationofasetofdatainordertoproperlydescribethevariousfeaturesofthatsetofdataarecalled:a. inferentialstatistics.b. totalqualitymanagement.c. sampling.d. descriptivestatistics.Q3.Theportionoftheuniversethathasbeenselectedforanalysisiscalled:a. asample.b. aframe.c. aparameter.d. as

9、tatistic.Q4.Asummarymeasurethatiscomputedtodescribeanumericalcharacteristicfromonlyasampleofthepopulationiscalled:a. aparameter.b. acensus.c. astatistic.d. thescientificmethod.Q5.Asummarymeasurethatiscomputedtodescribeacharacteristicofanentirepopulationiscalled:a. aparameter.b. acensus.c. astatistic

10、.d. totalqualitymanagement.Q6.Theprocessofusingsamplestatisticstodrawconclusionsaboutpopulationparametersiscalled:a. inferentialstatistics.b. experimentation.c. primarysources.d. descriptivestatistics.Q7.Whichofthefourmethodsofdatacollectionisinvolvedwhenapersonretrievesdatafromanonlinedatabase?a. p

11、ublishedsources.b. experimentation.c. surveying.d. observation.Q8.Whichofthefourmethodsofdatacollectionisinvolvedwhenpeopleareaskedtocompleteaquestionnaire?a. publishedsources.b. experimentation.c. surveying.d. observation.Q9.Whichofthefourmethodsofdatacollectionisinvolvedwhenapersonrecordstheuseoft

12、heLosAngelesfreewaysystem?a. publishedsources.b. experimentation.c. surveying.d. observation.Q10.Afocusgroupisanexampleofwhichofthefourmethodsofdatacollection?a. publishedsources.b. experimentation.c. surveying.d. observation.Q11.Whichofthefollowingistrueaboutresponserates?a. Thelongerthequestionnai

13、re,thelowertherate.b. Mailsurveysusuallyproducelowerresponseratesthanpersonalinterviewsortelephonesurveys.c. Questionwordingcanaffectaresponserate.d. d.Alloftheabove.Q12.Whichofthefollowingisareasonthatamanagerneedstoknowaboutstatistics?a. Toknowhowtoproperlypresentanddescribeinformation.b. Toknowho

14、wtodrawconclusionsaboutthepopulationbasedonsampleinformation.c. Toknowhowtoimproveprocesses.d. Alloftheabove.oScenario1-1Questions13-15refertothisscenario:Aninsurancecompanyevaluatesmanyvariablesaboutapersonbeforedecidingonanappropriaterateforautomobileinsurance.Someofthesevariablescanbeclassifiedas

15、categorical,discreteandnumerical,orcontinuousandnumerical.Q13.ReferringtoScenario1-1(above),thenumberofclaimsapersonhasmadeinthelastthreeyearsiswhattypeofvariable?a. Categorical.b. Discreteandnumerical.c. Continuousandnumerical.d. Noneoftheabove.Q14.ReferringtoScenario1-1(above),apersonsageiswhattyp

16、eofvariable?a. Categorical.b. Discreteandnumerical.c. Continuousandnumerical.d. Noneoftheabove.Q15.ReferringtoScenario1-1(above),apersonsgenderiswhattypeofvariable?a. Categorical.b. Discreteandnumerical.c. Continuousandnumerical.d. Noneoftheabove.6Q16.Whichofthefollowingcanbereducedbyproperinterview

17、ertraining?a. Samplingerror.b. Measurementerror.c. Coverageerror.d. Nonresponseerror.Scenario1-2Questions17-19refertothisscenario:MediterraneanfruitflieswerediscoveredinCaliforniaafewyearsagoandbadlydamagedtheorangesgrowninthatstate.Supposethemanagerofalargefarmwantedtostudytheimpactofthefruitflieso

18、ntheorangecropsonadailybasisovera6-weekperiod.Oneachdayarandomsampleoforangetreeswasselectedfromwithinarandomsampleofacres.Thedailyaveragenumberofdamagedorangespertreeandtheproportionoftreeshavingdamagedorangeswerecalculated.Q17.ReferringtoScenario1-2(above),thetwomainmeasurescalculatedeachday(i.e.,

19、averagenumberofdamagedorangespertreeandproportionoftreeshavingdamagedoranges)arecalleda. statistics.b. parameters.c. samples.d. populations.Q18.ReferringtoScenario1-2(above),thetwomainmeasurescalculatedeachday(i.e.,averagenumberofdamagedorangespertreeandproportionoftreeshavingdamagedoranges)maybeuse

20、donadailybasistoestimatetherespectivetruepopulation.a. estimates.b. parameters.c. statistics.d. frame.Q19.ReferringtoScenario1-2(above),inthisstudy,drawingconclusionsonanyonedayaboutthetruepopulationcharacteristicsbasedoninformationobtainedfromthesampleiscalleda. evaluation.b. descriptivestatistics.

21、c. inferentialstatistics.d. survey.oScenario1-3Questions20and21refertothisscenario:TheQualityAssuranceDepartmentofalargeurbanhospitalisattemptingtomonitorandevaluatepatientsatisfactionwithhospitalservices.Priortodischarge,arandomsampleofpatientsisaskedtofilloutaquestionnairetoratesuchservicesasmedic

22、alcare,nursing,therapy,laboratory,food,andcleaning.TheQualityAssuranceDepartmentpreparesweeklyreportsthatarepresentedattheBoardofDirectorsmeetingsandextraordinary/atypicalratingsareeasytoflag.Q20.ReferringtoScenario1-3(above),truepopulationcharacteristicsestimatedfromthesampleresultseachweekarecalle

23、d.a. inferences.b. parameters.c. estimates.d. data.Q21.ReferringtoScenario1-3(above),alistingofallhospitalisedpatientsinthisinstitutionoveraparticularweekwouldconstitutethe.a. sample.b. population.c. statistics.d. parameters.Scenario1-4Questions22-24refertothisscenario:Thefollowingarethequestionsgiv

24、entoSheilaDrucker-Ferrisinhercollegealumniassociationsurvey.Eachvariablecanbeclassifiedascategoricalornumerical,discreteorcontinuous.Q22.ReferringtoScenario1-4(above),thedataforthenumberofyearssincegraduationiscategorisedas:.a. numericaldiscrete.b. categorical.c. numericalcontinuous.d. noneoftheabov

25、e.Q23.ReferringtoScenario1-4(above),thedataforthenumberofsciencemajorsiscategorisedas:.a. categorical.b. numericalcontinuous.c. numericaldiscrete.d. noneoftheabove.Q24.ReferringtoScenario1-4(above),thedatafortabulatingthelevelofjobsatisfaction(High,Moderate,Low)iscategorisedas:.a. numericalcontinuou

26、s.b. categorical.c. numericaldiscrete.d. noneoftheabove.Topic2:OrganisingandPresentingdataQ1Thewidthofeachbarinahistogramcorrespondstothe:a. boundariesoftheclasses.b. numberofobservationsintheclasses.c. midpointoftheclasses.d. percentageofobservationsintheclasses.Q2Whenconstructingcharts,whichofthef

27、ollowingcharttypesisplottedattheclassmidpoints?a. Frequencyhistograms.b. Percentagepolygons.c. Cumulativerelativefrequencyogives.d. Relativefrequencyhistograms.Q3Whenpolygonsorhistogramsareconstructed,whichaxismustshowthetruezeroororigin?a. Thehorizontalaxis.b. Theverticalaxis.c. Boththehorizontalan

28、dverticalaxes.d. Neitherthehorizontalnortheverticalaxis.Q4Todeterminetheappropriatewidthofeachclassintervalinagroupedfrequencydistribution,we:a. dividetherangeofthedatabythenumberofdesiredclassintervals.b. dividethenumberofdesiredclassintervalsbytherangeofthedatac. takethesquarerootofthenumberofobse

29、rvations.d. takethesquareofthenumberofobservations.Q5Whengroupingdataintoclassesitisrecommendedthatwehave:a. lessthan5classes.b. between5and15classes.c. morethan15classes.d. between10and30classes.Q6Whichofthefollowingchartswouldgiveyouinformationregardingthenumberofobservationsuptoandincludingagiven

30、group?a. Frequencyhistograms.b. Polygons.c. Percentagepolygons.d. Cumulativerelativefrequencyogives.Q7Anothernameforanogiveisa:a. frequencyhistogram.b. polygon.c. percentagepolygon.d. cumulativepercentagepolygon.Q8Inanalyzingcategoricaldata,thefollowinggraphicaldeviceisNOTappropriate:a. barchart.b.

31、Paretodiagram.c. stemandleafdisplay.d. piechart.oTable2Theopinionsofasampleof200peoplebrokendownbygenderaboutthelatestcongressionalplantoeliminateanti-trustexemptionsforprofessionalbaseball.ForNeutralAgainstTotalsFemale385412104Male12364896Totals509060200Q9Table2(above)containstheopinionsofasampleof

32、200peoplebrokendownbygenderaboutthelatestcongressionalplantoeliminateanti-trustexemptionsforprofessionalbaseball.ReferringtoTable2,thenumberofpeoplewhoareneutraltotheplanis.a. 36b. 54c. 90200Q10ReferringtoTable2,thenumberofmaleswhoareagainsttheplanis.a. 12b. 48c. 6096Q11ReferringtoTable2,thepercenta

33、geofmalesamongthosewhoarefortheplanis.a. 12.5%b. 24%c. 25%76%Q12ReferringtoTable2,thepercentagewhoareagainsttheplanamongthefemalesis.a. 11.54%b. 20%c. 30%52%Topic3:NumericalDescriptiveStatisticsQ1Whichmeasureofcentraltendencycanbeusedforbothnumericalandcategoricalvariables?a. Mean.b. Median.c. Mode.

34、d. Quartiles.Q2Whichofthefollowingstatisticsisnotameasureofcentraltendency?a. Mean.b. Median.c. Mode.d. Q3.Q3WhichofthefollowingstatementsaboutthemedianisNOTtrue?a. Itismoreaffectedbyextremevaluesthanthemean.b. Itisameasureofcentraltendency.c. ItisequaltoQ2.d. Itisequaltothemodeinbell-shapeddistribu

35、tions.Q4Thevalueinadatasetthatappearsmostfrequentlyiscalled:a. themedian.b. themode.c. themean.d. thevariance.Q5Inaperfectlysymmetricaldistribution:a. themeanequalsthemedian.b. themedianequalsthemode.c. themeanequalsthemode.d. Alloftheabove.Q6Whenextremevaluesarepresentinasetofdata,whichofthefollowi

36、ngdescriptivesummarymeasuresaremostappropriate?a. CVandrange.b. Meanandstandarddeviation.c. Medianandinterquartilerange.d. Modeandvariance.Q7Thesmallerthespreadofscoresaroundthemean:a. thesmallertheinterquartilerange.b. thesmallerthestandarddeviation.c. thesmallerthecoefficientofvariation.d. Allthea

37、bove.Q8Inaright-skeweddistribution:a. themedianequalsthemean.b. themeanislessthanthemedian.c. themeanisgreaterthanthemedian.d. themeanislessthanthemode.Thedatabelowrepresentstheamountofgramsofcarbohydratesinaservingofbreakfastcereal.Table31115232919222120152517Q9ReferringtoTable3(above),themeancarbo

38、hydratesinthissampleisgrams.a. 15.25b. 19.73c. 21.4221.70Q10ReferringtoTable3(above),themediancarbohydrateamountinthecerealisgrams.a. 19b. 20c. 2121.5Q11ReferringtoTable3(above),the1stquartileofthecarbohydrateamountsisgrams.a. 15b. 20c. 2125Q12ReferringtoTable3(above),therangeinthecarbohydrateamount

39、sisgrams.a.16b.18c.20d.21Topic4:BasicsprobabilityanddiscreteprobabilitydistributionsInformationA,neededtoanswerQuestions1to2TheHealthandSafetycommitteeinalargeretailfirmisexaminingtherelationshipbetweenthenumberofdaysofsickleaveanemployeetakesandwhetheranemployeeworksonthedayshift(D)ornightshift(N).

40、Thecommitteelooksatasampleof50employeesandnoteswhichshifttheyworkonandwhetherthenumberofdaysofsickleavetheytakeinayearislessthan6days(L)or6ormoredays(M).Theinformationtheyobtainisshownbelow.Table4-1:FrequenciesNumberofdaysofsickleaveShift(L)Lessthan6(M)6orMoreTotal(D)Day81220(N)Night121830Total20305

41、0Table4-2:ProbablilitiesNumberofdaysofsickleaveShift(L)Lessthan6(M)6orMoreTotal(D)Day0(N)Night0.240.360.60Total0.400.601.00Q1UseInformationAtoanswerthisquestion.Whichofthefollowingstatementsaboutthevaluesinthetableofprobabilitiesisnotcorrect?a. Theprobabilityofanemployeetaking6ormoredayso

42、fsickleaveP(M)is0.6TheprobabilitythatanemployeeisontheNightShift(N)andtakeslessthan6daysofleave(L),iscalledaconditionalprobabilityP(N|L)=0.6Ifyouknowthatanemployeeisondayshift(D)thentheprobabilitythattheywilltakelessthan6daysofleave(L)istheconditionalprobabilityP(L|D)=0.4Theprobabilitythatanemployee

43、worksDayShift(D)ortakes6ormoredaysofleave(M)isfoundusingtheadditionruletobeP(DorM)=0.76TheyareallcorrectQ2TheanalystwishestousetheProbabilitiestablefromInformationAtodeterminewhethertheworkshiftvariableandthenumberofdaysofsickleavevariableareorarenotindependentvariables.Whichofthefollowingstatements

44、abouttheworkshiftandthenumberofdaysofsickleavevariablesiscorrect?a. ThesevariablesareindependentbecausethemarginalprobabilitiessuchasP(L)arethesameastheconditionalprobabilitiesP(L|D)ThesevariablesarenotindependentbecausethemarginalprobabilityP(L)isdifferentfromtheconditionalprobabilityP(N|L)Thesevar

45、iablesarenotindependentbecausethejointprobabilitiessuchasP(LandN)areequaltotheproductoftheprobabilitiesP(L).P(N).b. ThesevariablesaredependentbecausethemarginalprobabilitiessuchasP(L)areequaltotheconditionalprobabilityP(L|N)NoneoftheaboveInformationB,neededtoanswerQuestion3Supposethemanagerofahomewa

46、reretailerdecidesina5-minuteperiodnomorethan4customerscanarriveatacounter.Usingpastrecordsheobtainsthefollowingprobabilitydistributionforthepossiblenumberofcustomerswhocanarriveatacounter.Table4-3Arrivals(X)01234P(X).0.15Q3UseInformationBtoanswerthisquestion.Ifvaluesareroundedto3decimalpla

47、ceswhichofthefollowingisthecorrectpairofvaluesforthemean,thevarianceorstandarddeviationofthenumberofarrivalsatthecounter.a.Meanmu=2andvariancesigma-squared=1.265b.Meanmu=2.5andvariancesigma-squared=1.6c.Meanmu=2andstandarddeviationsigma=1.6d.Meanmu=2.4andvariancesigma-squared=1.6e.NoneoftheaboveInfo

48、rmationC,neededtoanswerQuestions4-6Thesectionmanagerinaninsurancecompanyisinterestedinevaluatinghowwellstaffattheinquirycounterhandlecustomercomplaints.Sheinterviewsasampleofn=6customerswhohavemadecomplaintsandaskseachofthemwhetherstaffhadhandledtheircomplaintswell.Eachinterviewiscalledatrial.Ifacus

49、tomersaystheircomplaintwashandledwellthisiscalledasuccess.ShethinksthataslongasthesepeopleareinterviewedindependentlyofeachotherthenthenumberofpeoplewhosaytheircomplaintwashandledwellisarandomvariablewithaBinomialprobabilitydistribution.Thesectionmanagerthinksthattheprobabilitythatacustomerscomplain

50、twillbehandledwellisp=0.75.Q4UseInformationCtoanswerthisquestion.Atotalofn=6peopleareinterviewedindependentlyofeachother.Whichofthefollowingstatementsabouttheprobabilitythat5outofthe6complaintswillbehandledwelliscorrecta. lessthan0.06b. between0.23and0.24c. morethan0.35d. between0.30and0.32Noneofthe

51、aboveQ5UsingInformationC,whichofthefollowingstatementsabouttheprobabilitythat4orlessofthe6complaintswillbehandledwelliscorrecta.lessthan0.36b.morethan0.52c.between0.45and0.475d.between0.15and0.175e.NoneoftheaboveQ6SupposethesectionmanagerfromInformationCisinterestedinthemeasuresofcentraltendencyandv

52、ariationforthenumberofcomplaintswhicharehandledwell.Whichofthefollowingsetsofvalues,wherevaluesareroundedto3decimalplaces,isthecorrectsetofvaluesa.Meanmu=4.5andvariancesigma-squared=:1.125b.Meanmu=4.5andvariancesigma-squared=:1.061c.Meanmu=1.5andvariancesigma-squared=:1.125d.Meanmu=1.5andstandarddev

53、iationsigma：=1.061e.NoneoftheaboveInformationD,neededtoanswerQuestions7-9Themanagerofalargeretailerthinksthatonereasonwhystaffatthecomplaintscounterfailtohandlecustomercomplaintswellisthatnotenoughstaffareallocatedtothiscounter.Pastexperiencehasshownthatthenumberofcustomerswhoarriveatthiscounterhasa

54、Poissondistributionwheretheaveragenumberwhoarriveeachhouris36.Hedecidestolookathowmanycustomersarelikelytoarriveatthecomplaintscounterduringa5-minuteperiod.Q7UseInformationDtoanswerthisquestion.Whichofthefollowingstatementsconcerningtheprobabilitythatexactly2customerswillarriveatthecounterina5-minut

55、eperiodiscorrecta.lessthan0.05b.between0.21and0.23c.between0.16and0.18d.morethan0.25e.NoneoftheaboveQ8UseInformationDtoanswerthisquestion.Whichofthefollowingstatementsconcerningtheprobabilitythat3ormorecustomerswillarriveatacounterina5-minuteperiodiscorrecta.between0.10and0.15b.lessthan0.23c.moretha

56、n0.77d.between0.60and0.55e.NoneoftheaboveQ9ThesectionmanagerfromInformationDisinterestedinthemeanandvarianceofthenumberofcustomerswhoarriveduringa1hourperiod.Whichofthefollowingisthecorrectsetofvaluesforthesetwomeasuresa.Meanmu=3andvariancesigma-squared=3b.Meanmu=36andstandarddeviationsigma=1.732c.M

57、eanmu=30andvariancesigma-squared:=30d. Meanmu=36andstandarddeviationsigma=6NoneoftheaboveTopic5:Normalprobabilitydistribution&samplingdistributionQ1Whichofthefollowingisnotapropertyofthenormaldistribution?a. Itisbell-shaped.b. Itisslightlyskewedleft.c. Itsmeasuresofcentraltendencyareallidentical.d. Itsrangeisfromnegati