统计学第六章.ppt
ProbabilityDistributionsChapter6
Definethetermsprobabilitydistributionandrandomvariable.Distinguishbetweendiscreteandcontinuousprobabilitydistributions.Calculatethemean,variance,andstandarddeviationofadiscreteprobabilitydistribution.Describethecharacteristicsofandcomputeprobabilitiesusingthebinomialprobabilitydistribution.Describethecharacteristicsofandcomputeprobabilitiesusingthehypergeometricprobabilitydistribution.DescribethecharacteristicsofandcomputeprobabilitiesusingthePoissonGOALS2
WhatisaProbabilityDistribution?Experiment:Tossacointhreetimes.Observethenumberofheads.Thepossibleresultsare:zeroheads,onehead,twoheads,andthreeheads.Whatistheprobabilitydistributionforthenumberofheads?3
ProbabilityDistributionofNumberofHeadsObservedin3TossesofaCoin4
CharacteristicsofaProbabilityDistribution5
RandomVariablesRandomvariable-aquantityresultingfromanexperimentthat,bychance,canassumedifferentvalues.6
TypesofRandomVariablesDiscreteRandomVariablecanassumeonlycertainclearlyseparatedvalues.ItisusuallytheresultofcountingsomethingContinuousRandomVariablecanassumeaninfinitenumberofvalueswithinagivenrange.Itisusuallytheresultofsometypeofmeasurement7
DiscreteRandomVariables-ExamplesThenumberofstudentsinaclass.Thenumberofchildreninafamily.Thenumberofcarsenteringacarwashinahour.NumberofhomemortgagesapprovedbyCoastalFederalBanklastweek. 8
ContinuousRandomVariables-ExamplesThedistancestudentstraveltoclass.Thetimeittakesanexecutivetodrivetowork.Thelengthofanafternoonnap.Thelengthoftimeofaparticularphonecall.9
FeaturesofaDiscreteDistributionThemainfeaturesofadiscreteprobabilitydistributionare:Thesumoftheprobabilitiesofthevariousoutcomesis1.00.Theprobabilityofaparticularoutcomeisbetween0and1.00.Theoutcomesaremutually