统计与精算学系stata01状态.pdfVIP

1.Instudyingtheeffectofanewtreatmentofacertainmedicalconditionforcom-

parisonwithaplacebo,thefollowingtableisobtainforatotalofpatients

TreatmentImprovedNotimprovedTotal

New35540

Placebo53035

(a)Considertestingthethatthepatients’improvementistof

treatmentagainsttheone-sidedalternativethatthenewtreatmentis

better.List,inatablewiththeorderoffrequenceofcells(1,1),(1,2),(2,1)

and(2,2),theconfigurationsof22tablesthatareneededfortheFisher

exacttest,andtheirassociatedprobabilityexpressiontogetherwiththemost

simplifiedexpressionsbycancelingoutcommonfactorsinthenumeratorand

thedenominator.Thencalculateandreportthe-value.Explainwhetherwe

canusethevariouschi-squaretestsintestingagainst.

(b)Considerthetwo-sidedalternativethatthenewtreatmentcanbter

orworse.DothehandcalculationforFisherexacttestinthepatternas

in(a).DemonstratethePearsonchi-square,FisherandMantel-Haenszel

chi-squarebyhandcalculation.

(c)PresentyourSAScodeandprintoutusingFREQtocomparewithyourhand

calculationin(b).

(d)Provideyourargumentonwhetherthesamplesizeislargeenoughforthe

chi-squaretestsregradingthisdataset.

(e)UsetheEXACTstateme