商务统计复习题

本文格式为Word版，下载可任意编辑——商务统计复习题AstudentmajoringinaccountingatGriffithUniversityistryingtodecideonthenumberoffirmstowhichsheshouldapply.Givenherworkexperience,academicresultsandextracurricularactivities,shehasbeentoldbyaplacementcounselorthatshecanexpecttoreceiveajobofferfrom60%ofthefirmstowhichsheapplies.Thestudentappliedto5firms.Assumingthecounselor’sestimateiscorrect,findtheprobabilitythatthestudentreceivesa.nooffers.

b.atleast2offers.

ThenumberofjoboffersthatshewillreceivefollowsaBinomialdistribution.LetXdenotethenumberofoffersshewillget.Thenumberoftrialsisn=5,withasuccessprobabilityp=0.6.x0a.P(X=0)=Cn(p)x(1?p)(n?x)=C5(0.6)0(0.4)(5?0)?0.01

b.P(X?2)=1-[P(X=0)+P(X=1)]=1-[0.01+0.08]=0.911.Fore-commercemerchants,gettingacustomertovisitaWebsiteisn’tenough.Merchants

mustalsopersuadeonlineshopperstospendmoneybycompletingapurchase.ExpertsatAndersenConsultingestimatedthat88%ofWebshoppersabandontheirvirtualshoppingcartsbeforecompletingtheirtransaction.Considerasampleof20customerswhovisitane-commerceWebsite,andassumethattheprobabilityacustomerwillleavethesite,andassumethattheprobabilityacustomerwillleavethesitebeforecompletingatransactionis0.88.

a.Whatistheexpectedvalue,ormean,ofthebinomialdistribution?1.76b.Whatisthestandarddeviationofthebinomialdistribution?1.45

c.Whatistheprobabilitythatall20ofthecustomerswillleavethesitewithoutcompleting

atransaction?0.078

d.Whatistheprobabilitythat18ormoreofthecustomerswillleavethesitewithout

completingatransaction?0.564

Timespentusinge-mailpersessionisnormallydistributedwithmean=8minutesandstd=2minutes.Ifrandomsamplesof25sessionswereselected,

a.Whatproportionofthesamplemeanwouldbebetween7.8and8.2minutes?b.Whatproportionofthesamplemeanwouldbebetween7.5and8minutes?

c.Ifrandomsamplesof100sessionswereselected,whatproportionofthesamplemeanwouldbebetween7.8and8.2minutes?????

DuringJuneandJulyof2023,theEuropeanUnionExecutiveCommissionconductedastudyof6,543Europeanadults.Ofthosesurveyed,56%saidthattheeurosinglecurrencywouldpromoteeconomicgrowthand73%knewthecorrectdateofthechangeover.Constructa95%confidenceintervalestimatefortheproportionofEuropeanadultswhobelievethattheeurowouldpromoteeconomicgrowth.

??EMBEDEquation.DSMT4??????

1.Thefollowingdatarepresentthemonthlyservicefeeindollarsifacustomer’saccountfallsbelowtheminimumrequired$1,500balanceforasampleof26banksfordirect-depositcustomers.Constructa95%confidenceintervalforthepopulationmeanmonthlyservicefeeindollarsifacustomer’saccountfallsbelowtheminimumrequiredbalance.

12??8??5??5??6??6??10??10??9??7??10??7??7????5??0??10??6??9??12??0??5??10??8??5??5??9??????EMBEDEquation.DSMT4??????

2.amanufacturerofflashlightbatteriestookasampleof13batteriesfromaday’sproductionandusedthemcontinuouslyuntiltheyfailedtowork.Thelifeofthebatteriesinhoursuntilfailureis:342??426??317??545??264