基础统计学(英文版)课件

Chapter11Chapter11ChapterOneWhatisStatistics?ONEUnderstandwhywestudystatistics.TWOExplainwhatismeantbydescriptivestatisticsandinferentialstatistics.THREEDistinguishbetweenaqualitativevariableandaquantitativevariable.FOUR

Distinguishbetweenadiscretevariableandacontinuousvariable.FIVEDistinguishamongthenominal,ordinal,interval,andratiolevels

ofmeasurement.SIXDefinethetermsmutuallyexclusiveandexhaustive.GOALSWhenyouhavecompletedthischapter,youwillbeableto:2ChapterOneWhatisStatistics?Whystudystatistics?NumericalinfoiseverywhereButhowdoweknowifconclusionsreportedareaccurate?StatisticaltechniquesareusedtomakedecisionsthataffectourlivesThisiswhyyoungerpeoplepaymoreforinsurance…KnowledgeofstatisticalmethodsatleasthelpsyouunderstandwhydecisionsaremadeInfutureyouwillmakedecisionsthatinvolvedata3Whystudystatistics?NumericalWhatisMeantbyStatistics?

Statistics

isthescienceofcollecting,organizing,presenting,analyzing,andinterpretingnumericaldatatoassistinmakingmoreeffectivedecisions.

Incommonusagestatisticsreferstonumericalinformation…..Butinthiscoursethetermhasawidermeaning….4WhatisMeantbyStatistics? SWhoUsesStatistics?

Statisticaltechniquesareusedextensivelybymanagersinmarketing,accounting,qualitycontrol,consumers,professionalsportspeople,hospitaladministrators,educators,politicians,physicians,gamblers,etc...5WhoUsesStatistics? StatisticTypesofStatistics

DescriptiveStatistics:Methodsoforganizing,summarizing,andpresentingdatainaninformativeway.EXAMPLE1:AGalluppollfoundthat49%ofthepeopleinasurveyknewthenameofthefirstbookoftheBible.Thestatistic49describesthenumberoutofevery100personswhoknewtheanswer.6TypesofStatistics DescriptivTypesofStatistics

DescriptiveStatistics:Methodsoforganizing,summarizing,andpresentingdatainaninformativeway.EXAMPLE2:AccordingtoConsumerReports,GeneralElectricwashingmachineownersreported9problemsper100machinesduring2002.Thestatistic9describesthenumberofproblemsoutofevery100machines.7TypesofStatistics DescriptivTypesofStatistics

DescriptiveStatistics:Methodsoforganizing,summarizing,andpresentingdatainaninformativeway.EXAMPLE3:TheCanadiangovernmentreportsthatthepopulationofCanadawas18,238,000in1961,21,568,000in1971,24,820,000in1981,28,031,000in1991,and31,050,700in2001.Ifwecalculatepercentagegrowthoverthedecadesitisalsodescriptivestatistics.8TypesofStatistics DescriptivTypesofStatistics

InferentialStatistics:Themethodsusedtodeterminesomethingaboutapopulation,basedonasample.

O

EXAMPLE1:IntheprecedingexampleonCanadianpopulationchanges,ifyouusethepastdatatoforecastthepopulationofCanadaintheyear2010orexpectedpercentageofgrowthfrom2000to2010,thenthisisconsideredinferentialstatistics.9TypesofStatistics InferentiTypesofStatistics

InferentialStatistics:Themethodsusedtodeterminesomethingaboutapopulation,basedonasample.

EXAMPLE2:Theaccountingdepartmentofalargefirmwillselectasampleoftheinvoicestocheckforaccuracyforalltheinvoicesofthecompany.10TypesofStatistics InferentiTypesofStatistics

InferentialStatistics:Themethodsusedtodeterminesomethingaboutapopulation,basedonasample.

EXAMPLE3:Winetasterssipafewdropsofwinetomakeadecisionwithrespecttoallthewinewaitingtobereleasedforsale.11TypesofStatistics InferentiPopulationvs.SamplePopulation

istheentiresetofindividualsorobjectsofinterestorthemeasurementsobtainedfromallindividualsorobjectsofinterest.Sample

isaportion,orpart,ofthepopulationofinterest12Populationvs.SamplePopulatioSeealsop.7Population:AllitemsSample:Itemsselectedfromthepopulation13Seealsop.7Population:AllitNB:don’tconfusepopulationinstatisticswithacountry’spopulation!ApopulationmightconsistofallthepeopleinNanaimobutalsomaymeanthePEratiosforallchemicalstocks,ortotalassetsofthe20largestbanksinNorthAmerica,totalcollectionofprices,ages,squarefootageofretailspaceinNanaimo,andsoon.14NB:don’tconfusepopulationiTypesofVariables

Fora

QualitativeorAttributevariable

thecharacteristicbeingstudiedisnonnumeric.EXAMPLES:Gender,religiousaffiliation,typeofautomobileowned,countryofbirth,eyecolourareexamples.15TypesofVariables ForaQualTypesofVariables

Ina

Quantitativevariableinformationisreportednumerically.EXAMPLES:balanceinyourchequingaccount,minutesremaininginclass,ornumberofchildreninafamily.16TypesofVariables EXAMPLES:bTypesofVariables

Quantitativevariablescanbeclassifiedaseitherdiscreteorcontinuous.

Discretevariables:canonlyassumecertainvaluesandthereareusually“gaps”betweenvalues.EXAMPLE:thenumberofbedroomsinahouse,orthenumberofhammerssoldatthelocalHomeDepot(1,2,3,…,etc).Butyoucannothave2.3bedroomsor10.6hammers…Thusdiscretevariablesresultfromcounting.17TypesofVariables QuantitativTypesofVariables

Acontinuousvariablecanassumeanyvaluewithinaspecifiedrange.

Examplesare:Thepressureinatire,theweightofaporkchop,ortheheightofstudentsinaclass.Typically,continuousvariablesaretheresultofmeasuringsomething.18TypesofVariables AcontinuouSummaryofTypesofVariables19SummaryofTypesofVariables1LevelsofMeasurementDatamaybeclassifiedintofourclassesorlevelsofmeasurement:nominal,ordinal,interval,andratio.

Nominallevel:Datathatisclassifiedandcounted.EXAMPLES:eyecolour,gender,religiousaffiliation.20LevelsofMeasurementDatamayLevelsofMeasurement

Mutuallyexclusive:Anindividual,object,ormeasurementisincludedinonlyonecategory.

Exhaustive:Eachindividual,object,ormeasurementmustappearinoneofthecategories.Nominaldatahavenoparticularorderorrankandaremutuallyexclusive.21LevelsofMeasurement ExhaustiMaritalStatus2000(population15yearsandolder)StatusNumberSingle(nevermarried)7,285,560Married(legally,separated,common-law)14,614,564Divorced1,452,000Widowed1,527,075Total24,879,199Thesedataareanominallevelofmeasurementbecauseitcanonlybeclassifiedintoclassesandtheorderofthemaritalstatusisnotimportant.Theclassesarealsomutuallyexclusiveandexhaustive.22MaritalStatus2000(populatioLevelsofMeasurement

Ordinallevel:involvesdataarrangedinsomeorder,butthedifferencesbetweendatavaluescannotbedeterminedoraremeaningless.EXAMPLE:Duringatastetestof4softdrinks,MountainDewwasrankednumber1,Spritenumber2,Seven-upnumber3,andOrangeCrushnumber4.23LevelsofMeasurement OrdinalLevelsofMeasurement

Intervallevelissimilartotheordinallevel,withtheadditionalpropertythatmeaningfulamountsofdifferencesbetweendatavaluescanbedetermined.Thereisnonaturalzeropoint.EXAMPLE:TemperatureontheCelsiusscale.0degreesdoesnotrepresenttheabsenceoftemperature,justthatitiscold!24LevelsofMeasurement IntervalLevelsofMeasurement

Ratiolevelistheintervallevelwithaninherentzerostartingpoint.Differencesandratiosaremeaningfulforthislevelofmeasurement.EXAMPLES:

Monthlyincomeofsurgeons,ordistancetraveledbymanufacturer’srepresentativespermonth.25LevelsofMeasurement EXAMPLES26262727282829293030Chapter131Chapter11ChapterOneWhatisStatistics?ONEUnderstandwhywestudystatistics.TWOExplainwhatismeantbydescriptivestatisticsandinferentialstatistics.THREEDistinguishbetweenaqualitativevariableandaquantitativevariable.FOUR

Distinguishbetweenadiscretevariableandacontinuousvariable.FIVEDistinguishamongthenominal,ordinal,interval,andratiolevels

ofmeasurement.SIXDefinethetermsmutuallyexclusiveandexhaustive.GOALSWhenyouhavecompletedthischapter,youwillbeableto:32ChapterOneWhatisStatistics?Whystudystatistics?NumericalinfoiseverywhereButhowdoweknowifconclusionsreportedareaccurate?StatisticaltechniquesareusedtomakedecisionsthataffectourlivesThisiswhyyoungerpeoplepaymoreforinsurance…KnowledgeofstatisticalmethodsatleasthelpsyouunderstandwhydecisionsaremadeInfutureyouwillmakedecisionsthatinvolvedata33Whystudystatistics?NumericalWhatisMeantbyStatistics?

Statistics

isthescienceofcollecting,organizing,presenting,analyzing,andinterpretingnumericaldatatoassistinmakingmoreeffectivedecisions.

Incommonusagestatisticsreferstonumericalinformation…..Butinthiscoursethetermhasawidermeaning….34WhatisMeantbyStatistics? SWhoUsesStatistics?

Statisticaltechniquesareusedextensivelybymanagersinmarketing,accounting,qualitycontrol,consumers,professionalsportspeople,hospitaladministrators,educators,politicians,physicians,gamblers,etc...35WhoUsesStatistics? StatisticTypesofStatistics

DescriptiveStatistics:Methodsoforganizing,summarizing,andpresentingdatainaninformativeway.EXAMPLE1:AGalluppollfoundthat49%ofthepeopleinasurveyknewthenameofthefirstbookoftheBible.Thestatistic49describesthenumberoutofevery100personswhoknewtheanswer.36TypesofStatistics DescriptivTypesofStatistics

DescriptiveStatistics:Methodsoforganizing,summarizing,andpresentingdatainaninformativeway.EXAMPLE2:AccordingtoConsumerReports,GeneralElectricwashingmachineownersreported9problemsper100machinesduring2002.Thestatistic9describesthenumberofproblemsoutofevery100machines.37TypesofStatistics DescriptivTypesofStatistics

DescriptiveStatistics:Methodsoforganizing,summarizing,andpresentingdatainaninformativeway.EXAMPLE3:TheCanadiangovernmentreportsthatthepopulationofCanadawas18,238,000in1961,21,568,000in1971,24,820,000in1981,28,031,000in1991,and31,050,700in2001.Ifwecalculatepercentagegrowthoverthedecadesitisalsodescriptivestatistics.38TypesofStatistics DescriptivTypesofStatistics

InferentialStatistics:Themethodsusedtodeterminesomethingaboutapopulation,basedonasample.

O

EXAMPLE1:IntheprecedingexampleonCanadianpopulationchanges,ifyouusethepastdatatoforecastthepopulationofCanadaintheyear2010orexpectedpercentageofgrowthfrom2000to2010,thenthisisconsideredinferentialstatistics.39TypesofStatistics InferentiTypesofStatistics

InferentialStatistics:Themethodsusedtodeterminesomethingaboutapopulation,basedonasample.

EXAMPLE2:Theaccountingdepartmentofalargefirmwillselectasampleoftheinvoicestocheckforaccuracyforalltheinvoicesofthecompany.40TypesofStatistics InferentiTypesofStatistics

InferentialStatistics:Themethodsusedtodeterminesomethingaboutapopulation,basedonasample.

EXAMPLE3:Winetasterssipafewdropsofwinetomakeadecisionwithrespecttoallthewinewaitingtobereleasedforsale.41TypesofStatistics InferentiPopulationvs.SamplePopulation

istheentiresetofindividualsorobjectsofinterestorthemeasurementsobtainedfromallindividualsorobjectsofinterest.Sample

isaportion,orpart,ofthepopulationofinterest42Populationvs.SamplePopulatioSeealsop.7Population:AllitemsSample:Itemsselectedfromthepopulation43Seealsop.7Population:AllitNB:don’tconfusepopulationinstatisticswithacountry’spopulation!ApopulationmightconsistofallthepeopleinNanaimobutalsomaymeanthePEratiosforallchemicalstocks,ortotalassetsofthe20largestbanksinNorthAmerica,totalcollectionofprices,ages,squarefootageofretailspaceinNanaimo,andsoon.44NB:don’tconfusepopulationiTypesofVariables

Fora

QualitativeorAttributevariable

thecharacteristicbeingstudiedisnonnumeric.EXAMPLES:Gender,religiousaffiliation,typeofautomobileowned,countryofbirth,eyecolourareexamples.45TypesofVariables ForaQualTypesofVariables

Ina

Quantitativevariableinformationisreportednumerically.EXAMPLES:balanceinyourchequingaccount,minutesremaininginclass,ornumberofchildreninafamily.46TypesofVariables EXAMPLES:bTypesofVariables

Quantitativevariablescanbeclassifiedaseitherdiscreteorcontinuous.

Discretevariables:canonlyassumecertainvaluesandthereareusually“gaps”betweenvalues.EXAMPLE:thenumberofbedroomsinahouse,orthenumberofhammerssoldatthelocalHomeDepot(1,2,3,…,etc).Butyoucannothave2.3bedroomsor10.6hammers…Thusdiscretevariablesresultfromcounting.47TypesofVariables QuantitativTypesofVariables

Acontinuousvariablecanassumeanyvaluewithinaspecifiedrange.

Examplesare:Thepressureinatire,theweightofaporkchop,ortheheightofstudentsinaclass.Typically,continuousvariablesaretheresultofmeasuringsomething.48TypesofVariables AcontinuouSummaryofTypesofVariables49SummaryofTypesofVariables1LevelsofMeasurementDatamaybeclassifiedintofourclassesorlevelsofmeasurement:nominal,ordinal,interval,andratio.

Nominallevel:Datathatisclassifiedandcounted.EXAMPLES:eyecolour,gender,religiousaffiliation.50LevelsofMeasurementDatamayLevelsofMeasurement

Mutuallyexclusive:Anindividual,object,ormeasurementisincludedinonlyonecategory.

Exhaustive:Eachindividual,object,ormeasurementmustappearinoneofthecategories.Nominaldatahave