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ID:58883958
大小:1.42 MB
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时间:2020-09-30
《Hypothesis_Testing(统计学假设检验)ppt课件.ppt》由会员上传分享,免费在线阅读,更多相关内容在教育资源-天天文库。
1、Chapter9INTRODUCTIONTOHYPOTHESISTESTINGStatisticsforBusiness(ENV)1HypothesisTesting9.1NullandAlternativeHypothesesandErrorsinTesting9.2zTestsaboutaPopulationwithknowns9.3tTestsaboutaPopulationwithunknowns2Hypothesistesting-1Researchersusuallycollectdatafromasamplea
2、ndthenusethesampledatatohelpanswerquestionsaboutthepopulation.Hypothesistestingisaninferentialstatisticalprocessthatuseslimitedinformationfromthesampledataastoreachageneralconclusionaboutthepopulation.3Ahypothesistestisaformalizedprocedurethatfollowsastandardserieso
3、foperations.Inthisway,researchershaveastandardizedmethodforevaluatingtheresultsoftheirresearchstudies.Hypothesistesting-24Thebasicexperimentalsituationforusinghypothesistestingispresentedhere.Itisassumedthattheparameterisknownforthepopulationbeforetreatment.Thepurp
4、oseoftheexperimentistodeterminewhetherornotthetreatmenthasaneffect.Isthepopulationmeanaftertreatmentthesameasordifferentfromthemeanbeforetreatment?Asampleisselectedfromthetreatedpopulationtohelpanswerthisquestion.5Proceduresofhypothesis-testing1.First,westateahypoth
5、esisaboutapopulation.Usuallythehypothesisconcernsthevalueofapopulationparameter.Forexample,wemighthypothesizethatthemeanIQforUICstudentsism=110.2.Next,weobtainarandomsamplefromthepopulation.Forexample,wemightselectarandomsampleofn=100UICstudents.3.Finally,wecomparet
6、hesampledatawiththehypothesis.Ifthedataareconsistentwiththehypothesis,wewillconcludethatthehypothesisisreasonable.Butifthereisabigdiscrepancybetweenthedataandthehypothesis,wewilldecidethatthehypothesisiswrong.6NullandAlternativeHypothesesThenullhypothesis,denotedH0,
7、isastatementofthebasicpropositionbeingtested.Itgenerallyrepresentsthestatusquo(astatementof“noeffect”or“nodifference”,orastatementofequality)andisnotrejectedunlessthereisconvincingsampleevidencethatitisfalse.The(scientificor)alternativehypothesis,denotedHa(orH1),isa
8、nalternative(tothenullhypothesis)statementthatwillbeacceptedonlyifthereisconvincingsampleevidencethatitistrue.Thesetwohypothesesaremutuall
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