ISYE 6414 MIDTERM PREP QUESTIONS
AND VERIFIED ANSWERS 2024
Wedcandassessdthedconstantdvariancedassumptiondindlineardregressiondbydplottingdthedres
idualsdvs.dfitteddvalues.d-dans✔✔True
IfdonedconfidencedintervaldindthedpairwisedcomparisondindANOVAdincludesdzero,dwedconcl
udedthatdthedtwodcorrespondingdmeansdaredplausiblydequal.d-dans✔✔True
Thedassumptiondofdnormalitydisdnotdrequireddindlineardregressiondtodmakedinferencedondth
edregressiondcoefficients.d-dans✔✔Falsed(Explanation:disdrequired)
Wedcannotdestimatedadmultipledlineardregressiondmodeldifdthedpredictingdvariablesdaredline
arlydindependent.d-dans✔✔Falsed(Explanation:dlinearlyddependent)
Ifdadpredictingdvariabledisdadcategoricaldvariabledwithd5dcategoriesdindadlineardregressiond
modeldwithoutdintercept,dwedwilldincluded5ddummydvariables.d-dans✔✔True
Ifdthednormalitydassumptionddoesdnotdholddfordadregression,dwedmaydusedadtransformation
dondthedresponsedvariable.d-dans✔✔True
Thedpredictiondofdthedresponsedvariabledhasdhigherduncertaintydthandthedestimationdofdthe
dmeandresponse.d-dans✔✔True
Statisticaldinferencedfordlineardregressiondunderdnormalitydreliesdondlargedsampledsize.d-
dans✔✔Falsed(Explanation:dsmalldsampledsizedisdfine)
Adnonlineardrelationshipdbetweendthedresponsedvariabledanddadpredictingdvariabledcannot
dbedmodeleddusingdregression.d-
dans✔✔Falsed(Explanation:dNonlineardrelationshipsdcandoftendbedmodeleddusingdlineardr
egressiondbydincludingdpolynomialdtermsdofdthedpredictingdvariable,dfordexample.)
, Assumptiondofdnormalitydindlineardregressiondisdrequireddfordconfidencedintervals,dpredicti
ondintervals,danddhypothesisdtesting.d-dans✔✔True
Ifdthedconfidencedintervaldfordadregressiondcoefficientdcontainsdthedvaluedzero,dwedinterpre
tdthatdthedregressiondcoefficientdisdplausiblydequaldtodzero.d-dans✔✔True
ThedsmallerdthedcoefficientdofddeterminationdordR-
squared,dthedhigherdthedvariabilitydexplaineddbythedsimpledlineardregression.d-
dans✔✔Falsed(Explanation:dThedlargerdthedR-squared)
Thedestimatorsdofdthedvariancedparameterdanddofdthedregressiondcoefficientsdindadregressi
ondmodeldaredrandomdvariables.d-dans✔✔True
Thedstandardderrordindlineardregressiondindicatesdhowdfardtheddatadpointsdaredfromdthedre
gressiondline,dondaverage.d-dans✔✔True
AdlineardregressiondmodeldisdadgooddfitdtodtheddatadsetdifdthedR-squareddisdaboved0.90.d-
dans✔✔Falsed(Explanation:dTheredaredotherdthingsdtodcheck:dassumptions,dMSE,detc.)
IndANOVA,dwedassumedthedvariancedofdthedresponsedvariabledisddifferentdfordeachdpopula
tion.d-dans✔✔Falsed(Explanation:disdthedsamedacrossdalldpopulations)
ThedF-testdindANOVAdcomparesdthedbetweendvariabilitydversusdthedwithindvariability.d-
dans✔✔True
Indtestingdfordsubsetsdofdcoefficientsdindadmultipledlineardregression,dthednulldhypothesisdw
edtest
fordisdthatdalldcoefficientsdaredequal;
H_0:dB_1d=dB_2d=d...d=dB_kfd-
dans✔✔Falsed(Explanation:dThednulldhypothesisdisdthatdalldcoefficientsdaredequaldtodzero;d
nonedaredsignificantdindpredictingdthedresponse.)
Thedonlydassumptionsdfordadsimpledlineardregressiondmodeldaredlinearity,dconstantdvarian
ce,danddnormality.d-dans✔✔False
Indadsimpledlineardregressiondmodel,dthedvariabledofdinterestdisdthedresponsedvariable.d-
dans✔✔True
Thedconstantdvariancedassumptiondisddiagnoseddbydplottingdthedpredictingdvariabledvs.dth
edresponsedvariable.d-dans✔✔False
βd1disdandunbiaseddestimatordfordβd0d.d-dans✔✔False
Thedestimatordσd^d2disdadfixeddvariable.d-dans✔✔False
AND VERIFIED ANSWERS 2024
Wedcandassessdthedconstantdvariancedassumptiondindlineardregressiondbydplottingdthedres
idualsdvs.dfitteddvalues.d-dans✔✔True
IfdonedconfidencedintervaldindthedpairwisedcomparisondindANOVAdincludesdzero,dwedconcl
udedthatdthedtwodcorrespondingdmeansdaredplausiblydequal.d-dans✔✔True
Thedassumptiondofdnormalitydisdnotdrequireddindlineardregressiondtodmakedinferencedondth
edregressiondcoefficients.d-dans✔✔Falsed(Explanation:disdrequired)
Wedcannotdestimatedadmultipledlineardregressiondmodeldifdthedpredictingdvariablesdaredline
arlydindependent.d-dans✔✔Falsed(Explanation:dlinearlyddependent)
Ifdadpredictingdvariabledisdadcategoricaldvariabledwithd5dcategoriesdindadlineardregressiond
modeldwithoutdintercept,dwedwilldincluded5ddummydvariables.d-dans✔✔True
Ifdthednormalitydassumptionddoesdnotdholddfordadregression,dwedmaydusedadtransformation
dondthedresponsedvariable.d-dans✔✔True
Thedpredictiondofdthedresponsedvariabledhasdhigherduncertaintydthandthedestimationdofdthe
dmeandresponse.d-dans✔✔True
Statisticaldinferencedfordlineardregressiondunderdnormalitydreliesdondlargedsampledsize.d-
dans✔✔Falsed(Explanation:dsmalldsampledsizedisdfine)
Adnonlineardrelationshipdbetweendthedresponsedvariabledanddadpredictingdvariabledcannot
dbedmodeleddusingdregression.d-
dans✔✔Falsed(Explanation:dNonlineardrelationshipsdcandoftendbedmodeleddusingdlineardr
egressiondbydincludingdpolynomialdtermsdofdthedpredictingdvariable,dfordexample.)
, Assumptiondofdnormalitydindlineardregressiondisdrequireddfordconfidencedintervals,dpredicti
ondintervals,danddhypothesisdtesting.d-dans✔✔True
Ifdthedconfidencedintervaldfordadregressiondcoefficientdcontainsdthedvaluedzero,dwedinterpre
tdthatdthedregressiondcoefficientdisdplausiblydequaldtodzero.d-dans✔✔True
ThedsmallerdthedcoefficientdofddeterminationdordR-
squared,dthedhigherdthedvariabilitydexplaineddbythedsimpledlineardregression.d-
dans✔✔Falsed(Explanation:dThedlargerdthedR-squared)
Thedestimatorsdofdthedvariancedparameterdanddofdthedregressiondcoefficientsdindadregressi
ondmodeldaredrandomdvariables.d-dans✔✔True
Thedstandardderrordindlineardregressiondindicatesdhowdfardtheddatadpointsdaredfromdthedre
gressiondline,dondaverage.d-dans✔✔True
AdlineardregressiondmodeldisdadgooddfitdtodtheddatadsetdifdthedR-squareddisdaboved0.90.d-
dans✔✔Falsed(Explanation:dTheredaredotherdthingsdtodcheck:dassumptions,dMSE,detc.)
IndANOVA,dwedassumedthedvariancedofdthedresponsedvariabledisddifferentdfordeachdpopula
tion.d-dans✔✔Falsed(Explanation:disdthedsamedacrossdalldpopulations)
ThedF-testdindANOVAdcomparesdthedbetweendvariabilitydversusdthedwithindvariability.d-
dans✔✔True
Indtestingdfordsubsetsdofdcoefficientsdindadmultipledlineardregression,dthednulldhypothesisdw
edtest
fordisdthatdalldcoefficientsdaredequal;
H_0:dB_1d=dB_2d=d...d=dB_kfd-
dans✔✔Falsed(Explanation:dThednulldhypothesisdisdthatdalldcoefficientsdaredequaldtodzero;d
nonedaredsignificantdindpredictingdthedresponse.)
Thedonlydassumptionsdfordadsimpledlineardregressiondmodeldaredlinearity,dconstantdvarian
ce,danddnormality.d-dans✔✔False
Indadsimpledlineardregressiondmodel,dthedvariabledofdinterestdisdthedresponsedvariable.d-
dans✔✔True
Thedconstantdvariancedassumptiondisddiagnoseddbydplottingdthedpredictingdvariabledvs.dth
edresponsedvariable.d-dans✔✔False
βd1disdandunbiaseddestimatordfordβd0d.d-dans✔✔False
Thedestimatordσd^d2disdadfixeddvariable.d-dans✔✔False
