大学课件-商务与经济统计习题答案（第8版，中文版）SBE8-SM09

9-1Chapter9HypothesisTestingLearningObjectives1.Learnhowtoformulateandtesthypothesesaboutapopulationmeanand/orapopulationproportion.2.Understandthetypesoferrorspossiblewhenconductingahypothesistest.3.Beabletodeterminetheprobabilityofmakingvariouserrorsinhypothesistests.4.Knowhowtocomputeandinterpretp-values.5.Beabletodeterminethesizeofasimplerandomsamplenecessarytokeeptheprobabilityofhypothesistestingerrorswithinacceptablelimits.6.Knowthedefinitionofthefollowingterms:nullhypothesisone-tailedtestalternativehypothesistwo-tailedtesttypeIerrorp-valuetypeIIerroroperatingcharacteristiccurvecriticalvaluepowercurvelevelofsignificanceChapter99-2Solutions:1.a.H0:600Manager’sclaim.Ha:600b.Wearenotabletoconcludethatthemanager’sclaimiswrong.c.Themanager’sclaimcanberejected.Wecanconcludethat400.2.a.H0:14Ha:14Researchhypothesisb.Thereisnostatisticalevidencethatthenewbonusplanincreasessalesvolume.c.Theresearchhypothesisthat14issupported.Wecanconcludethatthenewbonusplanincreasesthemeansalesvolume.3.a.H0:=32SpecifiedfillingweightHa:32Overfillingorunderfillingexistsb.Thereisnoevidencethattheproductionlineisnotoperatingproperly.Allowtheproductionprocesstocontinue.c.Conclude32andthatoverfillingorunderfillingexists.Shutdownandadjusttheproductionline.4.a.H0:220Ha:220Researchhypothesistoseeifmeancostislessthan$220.b.Weareunabletoconcludethatthenewmethodreducescosts.c.Conclude220.Considerimplementingthenewmethodbasedontheconclusionthatitlowersthemeancostperhour.5.a.TheTypeIerrorisrejectingH0whenitistrue.Inthiscase,thiserroroccursiftheresearcherconcludesthatthemeannewspaper-readingtimeforindividualsinmanagementpositionsisgreaterthanthenationalaverageof8.6minuteswheninfactitisnot.b.TheTypeIIerrorisacceptingH0whenitisfalse.Inthiscase,thiserroroccursiftheresearcherconcludesthatthemeannewspaper-readingtimeforindividualsinmanagementpositionsislessthanorequaltothenationalaverageof8.6minuteswheninfactitisgreaterthan8.6minutes.6.a.H0:1Thelabelclaimorassumption.Ha:1b.Claiming1whenitisnot.Thisistheerrorofrejectingtheproduct’sclaimwhentheclaimistrue.HypothesisTesting9-3c.Concluding1whenitisnot.Inthiscase,wemissthefactthattheproductisnotmeetingitslabelspecification.7.a.H0:8000Ha:8000Researchhypothesistoseeiftheplanincreasesaveragesales.b.Claiming8000whentheplandoesnotincreasesales.Amistakecouldbeimplementingtheplanwhenitdoesnothelp.c.Concluding8000whentheplanreallywouldincreasesales.Thiscouldleadtonotimplementingaplanthatwouldincreasesales.8.a.H0:220Ha:220b.Claiming220whenthenewmethoddoesnotlowercosts.Amistakecouldbeimplementingthemethodwhenitdoesnothelp.c.Concluding220whenthemethodreallywouldlowercosts.Thiscouldleadtonotimplementingamethodthatwouldlowercosts.9.a.z=-1.645RejectH0ifz-1.645b.9.46101.91/2/50xzsnRejectH0;concludeHaistrue.10.a.z=2.05RejectH0ifz2.05b.16.5151.36/7/40xzsnc.Areafromz=0toz=1.36is.4131p-value=.5000-.4131=.0869d.DonotrejectH011.RejectH0ifz-1.645a.22252.50/12/100xznRejectH0b.2425.8312/100zDonotrejectH0Chapter99-4c.23.5251.2512/100zDonotrejectH0d.22.8251.8312/100zRejectH012.a.p-value=.5000-.4656=.0344RejectH0b.p-value=.5000-.1736=.3264DonotrejectH0c.p-value=.5000-.4332=.0668DonotrejectH0d.z=3.09isthelargesttablevaluewith.5000-.4990=.001areaintail.Forz=3.30,thep-valueislessthan.001orapproximately0.RejectH0.e.Sincezistotheleftofthemeanandtherejectionregionisintheuppertail,p-value=.5000+.3413=.8413.DonotrejectH0.13.a.H0:1056Ha:1056b.RejectH0ifz-1.645c.091010561.83/1600/400xzsnd.RejectH0andconcludethatthemeanrefundof“lastminute”filersislessthan$1056.e.p-value=.5000-.4664=.033614.a.z.01=2.33RejectH0ifz2.33b.7.256.703.11/2.5/200xzsnc.RejectH0;concludethemeantelevisionviewingtimeperdayisgreaterthan6.70.15.a.z.05=1.645RejectH0ifz-1.645b.930010,1921.98/4500/100xzsnc.RejectH0;concludethatthemeansalespriceofusedcarsislessthanthenationalaverage.16.a.H0:Ha:13HypothesisTesting9-5b.z.01=2.33RejectH0ifz-2.33c.10.8132.88/9.2/145xzsnd.RejectH0;concludeCanadianmeaninternetusageislessthan13hourspermonth.Note:p-value=.00217.a.H0:15Ha:15b.17152.96/4/35xzsnc.p-value=.5000-.4985=.0015d.RejectH0;thepremiumrateshouldbecharged.18.a.H0:5.72Ha:5.72b.5.985.722.12/1.24/102xzsnc.p-value=.5000-.4830=.0170d.p-value;rejectH0.ConcludeteensinChicagohaveameanexpendituregreaterthan5.72.19.a.H0:181,900Ha:181,900b.166,400181,9002.93/33,500/40xzsnc.p-value=.5000-.4983=.0017d.p-value;rejectH0.ConcludemeansellingpriceinSouthislessthanthenationalmeansellingprice.20.a.H0:37,000Ha:37,000b.38,10037,0001.47/5200/48xzsnChapter99-6c.p-value=.5000-.4292=.0708d.p-value;donotrejectH0.CannotconcludepopulationmeansalaryhasincreasedinJune2001.21.a.RejectH0ifz-1.96orz1.96b.zxsn/../.108102536240RejectH0;concludeHaistrue.22.a.RejectH0ifz-2.33orz2.33b.zxsn/./.14215550113c.p-value=(2)(.5000-.3708)=.2584d.DonotrejectH023.RejectH0ifz-1.96orz1.96a.22252.6810/80zRejectH0b.27251.7910/80zDonotreje