Chapter 1 j
Data and Statistics
j j
LearningjObjectives
1. Obtainjanjappreciationjforjthejbreadthjofjstatisticaljapplicationsjinjbusinessjandjeconomics.
2. Understandjthejmeaningjofjthejtermsjelements,jvariables,jandjobservationsjasjtheyjarejusedjinjstati
stics.
3. Obtainjanjunderstandingjofjthejdifferencejbetweenjcategorical,jquantitative,jcross-
sectional,jandjtimejseriesjdata.
4. Learnjaboutjthejsourcesjofjdatajforjstatisticaljanalysisjbothjinternaljandjexternaljtojthejfirm.
5. Bejawarejofjhowjerrorsjcanjarisejinjdata.
6. Knowjthejmeaningjofjdescriptivejstatisticsjandjstatisticaljinference.
7. Bejablejtojdistinguishjbetweenjajpopulationjandjajsample.
8. Understandjthejrolejajsamplejplaysjinjmakingjstatisticaljinferencesjaboutjthejpopulation.
9. Knowjthejmeaningjofjthejtermsjanalytics,jbigjdatajandjdatajmining.
10. Bejawarejofjethicaljguidelinesjforjstatisticaljpractice.
,Solutions:
1. Statisticsjcanjbejreferredjtojasjnumericaljfacts.jInjajbroaderjsense,jstatisticsjisjthejfieldjofjstudyjdeal
ingjwithjthejcollection,janalysis,jpresentation,jandjinterpretationjofjdata.
2. a. Thejtenjelementsjarejthejtenjtabletjcomputers.
b. Fivejvariables:jCostj($),jOperatingjSystem,jDisplayjSizej(inches),jBatteryjLifej(hours),jCPUjMa
nufacturer
c. Categoricaljvariables:jOperatingjSystemjandjCPUjManufacturer
Quantitativejvariables:jCostj($),jDisplayjSizej(inches),jandjBatteryjLifej(hours)
d. j
Variable MeasurementjScale
Costj($) Ratio
OperatingjSystem Nominal
DisplayjSizej(inches) Ratio
BatteryjLifej(hours) Ratio
jj CPUjManufacturer Nominal
3. a. Averagejcostj=j5829/10j=j$582.90
b. AveragejcostjwithjajWindowsjoperatingjsystemj=j3616/5j=j$723.20jA
veragejcostjwithjanjAndroidjoperatingjsystemj=j1714/4j=j$428.5jTheja
veragejcostjwithjajWindowsjoperatingjsystemjisjmuchjhigher.
c. 2jofj10jorj20%jusejajCPUjmanufacturedjbyjTIjOMAP.
d. 4jofj10jorj40%jusejanjAndroidjoperatingjsystem.
4. a.
Therejarejeightjelementsjinjthisjdatajset;jeachjelementjcorrespondsjtojonejofjthejeightjmodel
sjofjcordlessjtelephones.
b. Categoricaljvariables:jVoicejQualityjandjHandsetjonjBasejQ
uantitativejvariables:jPrice,jOveralljScore,jandjTalkjTime
c. Pricej–jratiojmeasurement
OveralljScorej–
jinterval jmeasurement jVoice jQualityj–
jordinaljmeasurementjHandsetjonjBasej–
jnominaljmeasurementjTalkjTimej–
jratiojmeasurement
5. a. AveragejPricej=j545/8j=j$68.13
b. AveragejTalkjTimej=j71/8j=j8.875jhours
c. PercentagejratedjExcellent:j 2jofj8 2/8j=j.25,jorj25%
4j-j2
,6. a. Categorical
b. Quantitative
c. Categorical
d. Quantitative
e. Quantitative
7. a. Sincejtherejarejfivejchoices,jthejresponsejisjajcategoricaljresponse.
b. Thejfivejresponsesjarejthejlabelsjforjthejcustomerjresponses.j Ajnominaljscalejisjbeingjused.
8. a. 762
b. Categorical
c. Percentages
d. .67(762)j=j510.54
510jorj511jrespondentsjsaidjtheyjwantjthejamendmentjtojpass.
9. a. ThejpopulationjisjemployedjindividualsjinjthejUnitedjStatesjagedj25–29.
b. Havejyoujearnedjajbachelor’sjdegreej(orjhigher)?
c. Sincejthejresponsejisjyesjorj no,jthejresponsejisjcategorical.
10. a. Categorical
b. Percentages
c. 44jofj1080jrespondentsjorjapproximatelyj4%jstronglyjagreejwithjallowingjdriversjofjmotorjvehiclesjtojta
lkjonjajhand-heldjcelljphonejwhilejdriving.
d. 165jofjthej1080jrespondentsjorj15%jofjsaidjtheyjsomewhatjdisagreejandj741jorj69%jsaidjtheyjstrongl
yjdisagree.jThus,jtherejdoesjnotjappearjtojbejgeneralj supportjforjallowingjdriversjofjmotorjvehiclesjtojt
alkjonjajhand-heldjcelljphonejwhilejdriving.
11. a. Sincejthejrespondentsjanswerjwithjsomejtimejinterval,jthejresponsejisjcategorical.jb.
.53(1503)j=j796.59jorjapproximatelyj797
c. .10(1503)j=j150.3jorjapproximatelyj150
12. a. ThejpopulationjisjalljvisitorsjcomingjtojthejstatejofjHawaii.
b. Sincejairlinejflightsjcarryjthejvastjmajorityjofjvisitorsjtojthejstate,jthejusejofjquestionnairesjforjpasse
ngersjduringjincomingjflightsjisjajgoodjwayjtojreachjthisjpopulation.jThejquestionnairejactuallyjapp
earsjonjthejbackjofjajmandatoryjplantsjandjanimalsjdeclarationjformjthatjpassengersjmustjcompletej
duringjthejincomingjflight.jAjlargejpercentagejofjpassengersjcompletejthejvisitorjinformationjquesti
onnaire.
4j-j3
©j2021jCengagejLearning.jAlljRightsjReserved.
Mayjnotjbejscanned,jcopiedjorjduplicated,jorjpostedjtojajpubliclyjaccessiblejwebsite,jinjwholejorjinjpart.
, c. Questionsj1jandj4jprovidejquantitativejdatajindicatingjthejnumberjofjvisitsjandjthejnumberjofjdaysjinjHa
waii.jQuestionsj2jandj3jprovidejcategoricaljdatajindicatingjthejcategoriesjofjreasonjforjthejtripjandjwher
ejthejvisitorjplansjtojstay.
13. a. Facebookjworldwidejadvertisingjrevenue.
b. Quantitative
c. Timejseries
d. Facebookjadvertisingjrevenuejisjincreasingjatjanjincreasingjratejoverjtime.
14. a. Thejgraphjofjthejtimejseriesjfollows:
Hertz Dollar Avis
350
300
250
CarsjinjServicej(1000s)
200
150
100
50
0
Yea jrj 1 Yea jrj 2 Yea jrj 3 Yea jrj 4
b. InjYearj1jandjYearj2jHertzjwasjthejclearjmarketjsharejleader.jInjYearj3jandjYearj4jHertzjandjAvisjhavej
approximatelyjthejsamejmarketjshare.jThejmarketjsharejforjDollarjappearsjtojbejdeclining.
c. ThejbarjchartjforjYearj4jisjshownjbelow.
4j-j4
Data and Statistics
j j
LearningjObjectives
1. Obtainjanjappreciationjforjthejbreadthjofjstatisticaljapplicationsjinjbusinessjandjeconomics.
2. Understandjthejmeaningjofjthejtermsjelements,jvariables,jandjobservationsjasjtheyjarejusedjinjstati
stics.
3. Obtainjanjunderstandingjofjthejdifferencejbetweenjcategorical,jquantitative,jcross-
sectional,jandjtimejseriesjdata.
4. Learnjaboutjthejsourcesjofjdatajforjstatisticaljanalysisjbothjinternaljandjexternaljtojthejfirm.
5. Bejawarejofjhowjerrorsjcanjarisejinjdata.
6. Knowjthejmeaningjofjdescriptivejstatisticsjandjstatisticaljinference.
7. Bejablejtojdistinguishjbetweenjajpopulationjandjajsample.
8. Understandjthejrolejajsamplejplaysjinjmakingjstatisticaljinferencesjaboutjthejpopulation.
9. Knowjthejmeaningjofjthejtermsjanalytics,jbigjdatajandjdatajmining.
10. Bejawarejofjethicaljguidelinesjforjstatisticaljpractice.
,Solutions:
1. Statisticsjcanjbejreferredjtojasjnumericaljfacts.jInjajbroaderjsense,jstatisticsjisjthejfieldjofjstudyjdeal
ingjwithjthejcollection,janalysis,jpresentation,jandjinterpretationjofjdata.
2. a. Thejtenjelementsjarejthejtenjtabletjcomputers.
b. Fivejvariables:jCostj($),jOperatingjSystem,jDisplayjSizej(inches),jBatteryjLifej(hours),jCPUjMa
nufacturer
c. Categoricaljvariables:jOperatingjSystemjandjCPUjManufacturer
Quantitativejvariables:jCostj($),jDisplayjSizej(inches),jandjBatteryjLifej(hours)
d. j
Variable MeasurementjScale
Costj($) Ratio
OperatingjSystem Nominal
DisplayjSizej(inches) Ratio
BatteryjLifej(hours) Ratio
jj CPUjManufacturer Nominal
3. a. Averagejcostj=j5829/10j=j$582.90
b. AveragejcostjwithjajWindowsjoperatingjsystemj=j3616/5j=j$723.20jA
veragejcostjwithjanjAndroidjoperatingjsystemj=j1714/4j=j$428.5jTheja
veragejcostjwithjajWindowsjoperatingjsystemjisjmuchjhigher.
c. 2jofj10jorj20%jusejajCPUjmanufacturedjbyjTIjOMAP.
d. 4jofj10jorj40%jusejanjAndroidjoperatingjsystem.
4. a.
Therejarejeightjelementsjinjthisjdatajset;jeachjelementjcorrespondsjtojonejofjthejeightjmodel
sjofjcordlessjtelephones.
b. Categoricaljvariables:jVoicejQualityjandjHandsetjonjBasejQ
uantitativejvariables:jPrice,jOveralljScore,jandjTalkjTime
c. Pricej–jratiojmeasurement
OveralljScorej–
jinterval jmeasurement jVoice jQualityj–
jordinaljmeasurementjHandsetjonjBasej–
jnominaljmeasurementjTalkjTimej–
jratiojmeasurement
5. a. AveragejPricej=j545/8j=j$68.13
b. AveragejTalkjTimej=j71/8j=j8.875jhours
c. PercentagejratedjExcellent:j 2jofj8 2/8j=j.25,jorj25%
4j-j2
,6. a. Categorical
b. Quantitative
c. Categorical
d. Quantitative
e. Quantitative
7. a. Sincejtherejarejfivejchoices,jthejresponsejisjajcategoricaljresponse.
b. Thejfivejresponsesjarejthejlabelsjforjthejcustomerjresponses.j Ajnominaljscalejisjbeingjused.
8. a. 762
b. Categorical
c. Percentages
d. .67(762)j=j510.54
510jorj511jrespondentsjsaidjtheyjwantjthejamendmentjtojpass.
9. a. ThejpopulationjisjemployedjindividualsjinjthejUnitedjStatesjagedj25–29.
b. Havejyoujearnedjajbachelor’sjdegreej(orjhigher)?
c. Sincejthejresponsejisjyesjorj no,jthejresponsejisjcategorical.
10. a. Categorical
b. Percentages
c. 44jofj1080jrespondentsjorjapproximatelyj4%jstronglyjagreejwithjallowingjdriversjofjmotorjvehiclesjtojta
lkjonjajhand-heldjcelljphonejwhilejdriving.
d. 165jofjthej1080jrespondentsjorj15%jofjsaidjtheyjsomewhatjdisagreejandj741jorj69%jsaidjtheyjstrongl
yjdisagree.jThus,jtherejdoesjnotjappearjtojbejgeneralj supportjforjallowingjdriversjofjmotorjvehiclesjtojt
alkjonjajhand-heldjcelljphonejwhilejdriving.
11. a. Sincejthejrespondentsjanswerjwithjsomejtimejinterval,jthejresponsejisjcategorical.jb.
.53(1503)j=j796.59jorjapproximatelyj797
c. .10(1503)j=j150.3jorjapproximatelyj150
12. a. ThejpopulationjisjalljvisitorsjcomingjtojthejstatejofjHawaii.
b. Sincejairlinejflightsjcarryjthejvastjmajorityjofjvisitorsjtojthejstate,jthejusejofjquestionnairesjforjpasse
ngersjduringjincomingjflightsjisjajgoodjwayjtojreachjthisjpopulation.jThejquestionnairejactuallyjapp
earsjonjthejbackjofjajmandatoryjplantsjandjanimalsjdeclarationjformjthatjpassengersjmustjcompletej
duringjthejincomingjflight.jAjlargejpercentagejofjpassengersjcompletejthejvisitorjinformationjquesti
onnaire.
4j-j3
©j2021jCengagejLearning.jAlljRightsjReserved.
Mayjnotjbejscanned,jcopiedjorjduplicated,jorjpostedjtojajpubliclyjaccessiblejwebsite,jinjwholejorjinjpart.
, c. Questionsj1jandj4jprovidejquantitativejdatajindicatingjthejnumberjofjvisitsjandjthejnumberjofjdaysjinjHa
waii.jQuestionsj2jandj3jprovidejcategoricaljdatajindicatingjthejcategoriesjofjreasonjforjthejtripjandjwher
ejthejvisitorjplansjtojstay.
13. a. Facebookjworldwidejadvertisingjrevenue.
b. Quantitative
c. Timejseries
d. Facebookjadvertisingjrevenuejisjincreasingjatjanjincreasingjratejoverjtime.
14. a. Thejgraphjofjthejtimejseriesjfollows:
Hertz Dollar Avis
350
300
250
CarsjinjServicej(1000s)
200
150
100
50
0
Yea jrj 1 Yea jrj 2 Yea jrj 3 Yea jrj 4
b. InjYearj1jandjYearj2jHertzjwasjthejclearjmarketjsharejleader.jInjYearj3jandjYearj4jHertzjandjAvisjhavej
approximatelyjthejsamejmarketjshare.jThejmarketjsharejforjDollarjappearsjtojbejdeclining.
c. ThejbarjchartjforjYearj4jisjshownjbelow.
4j-j4
