数据分析8(1).doc

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1、Question1Wemodeledthegasmileageof398carsbuiltinthe1970'sandearly1980*susingenginedisplacement(incubicinches)/yearofmanufactureinrelationto1970(e.g.4meansthecarwasbuiltin1974;12meansbuiltin1982,etc.),andmanufacturingsite(domestictotheUSA=0;foreigntotheUSA=1).Theregressionoutputisprovidedbelow.No

2、tethatdomesticistherefereneelevelformanufacturingsite.EstimateStd・ErrortvaluePr(>

3、t

4、)(Intercept)26.860.8730.750.0000displacement-0.040.00・16.420.0000year0.720.0612.480.0000site:foreign2.210.544.080.0001Whichofthefollowingisthedegreesoffreedomassociatedwiththep-valueforsite?ScoreYourAnswer39832T

5、otal0.00/1.00QuestionExplanationThisquestionreferstothefollowinglearningobjective(s):Notethatthep・valuesassociatedwitheachpredictorareconditionalonothervariablesbeingincludedinthemodel,sotheycanbeusedtoassessifagivenpredictorissignificant,giventhatallothersareinthemodel.Thesep-valuesarecalculat

6、edbasedonafdistributionwithn~degreesoffreedom.Question2Wemodeledthegasmileageof398carsbuiltinthe1970sandearly1980?susingenginedisplacement(incubicinches),yearofmanufactureinrelationto1970(e.g.4meansthecarwasbuiltin1974;12meansbuiltin1982,etc)andmanufacturingsite(domestictotheUSA=0;foreigntotheU

7、SA二1).Theregressionoutputisprovidedbelow・Notethatdomesticisthereferencelevelformanufacturingsite.EstimateStd・ErrortvaluePr(>

8、t)(Intercept)26.860.8730.750.0000displacement-0.040.00-16.420.0000year0.720.0612.480.0000site:foreign2.210.544.080.0001Whichofthefollowingisthecorrectpredictedgasmileage(

9、inmilespergallon)foradomesticcarwithanenginedisplacementof350cubicinchesbuiltin1975?YourAnswerScoreExplanationthereferencelevelofsite.-0.04X350+072X1975—0.04X350+0.72X5+2.2126.86-0.04X350+0.72X5Total0.00/1.00QuestionExplanationThisquestionreferstothefollowinglearningobjective(s):Definethemultip

10、lelinearregressionmodelasJ/A=力0+01A1+B2X2+…+BkXkwheretherearekpredictors(explanatoryvariables).Question3Wemodeledthegasmileageof398carsbuiltinthe1970'sandearly1980*susingenginedisplacement(incubicinches)/yearofmanufactureinrelatio