1/1POINTS
Afitnesscenterclaimsthathemeanamountoftimethatapersonspendsathegym pervisitis33 minutes.Identifythenulhypothesis,H0,andthealternative hypothesis,Ha,intermsoftheparameterμ.
H0:μ≠33;Ha:μ=33 H0:μ=33;Ha:μ
...
1/1POINTS
Afitnesscenterclaimsthathemeanamountoftimethatapersonspendsathegym pervisitis33 minutes.Identifythenulhypothesis,H0,andthealternative hypothesis,Ha,intermsoftheparameterμ.
H0:μ≠33;Ha:μ=33 H0:μ=33;Ha:μ≠33 H0:μ≥33;Ha:μ<33
H0:μ≤33;Ha:μ>33
AnswerExplanation
Corectanswer:
H0:μ=33;Ha:μ≠33
Letheparameterμ beusedtorepresenthemean.Thenulhypothesisisalways statedwithsomeform ofequality:equal(=),greaterthanorequalto(≥),orlessthan orequalto(≤).Therefore,inthiscase,thenulhypothesisH0 isμ=33.The alternativehypothesisiscontradictorytothenulhypothesis,soHa isμ≠33.
QUESTION2 1/1POINTS
Theanswerchoicesbelowrepresentdifferenthypothesistests.Whichofthechoices areright-tailedtests?Selectalcorrectanswers.
•
H0:X≥17.1,Ha:X<17.1
•
•
H0:X=14.4,Ha:X≠14.4
•
•
H0:X≤3.8,Ha:X>3.8
•
•
H0:X≤7.4,Ha:X>7.4
•
•
H0:X=3.3,Ha:X≠3.3
•
AnswerExplanation
Corectanswer:
Remembertheformsofthehypothesistests.
Right-tailed:H0:X≤X0,Ha:X>X0.
Left-tailed:H0:X≥X0,Ha:X
7.4
H0:X≤3.8,Ha:X>3.8
QUESTION3 0/1POINTS
FindtheType Ierrorgiventhathenulhypothesis,H0,is:abuildinginspectorclaims thatnomorethan15% ofstructuresinthecountywerebuiltwithoutpermits.
Thebuildinginspectorthinksthatnomorethan15% ofthestructuresinthecounty werebuiltwithoutpermitswhen,infact,nomorethan15% ofthestructuresrealywere builtwithoutpermits.
Thebuildinginspectorthinksthatmorethan15% ofthestructuresinthecountywere builtwithoutpermitswhen,infact,morethan15% ofthestructuresrealywerebuilt withoutpermits.
Thebuildinginspectorthinksthatmorethan15% ofthestructuresinthecountywere builtwithoutpermitswhen,infact,atmost15% ofthestructureswerebuiltwithout permits.
Thebuildinginspectorthinksthatnomorethan15% ofthestructuresinthecounty werebuiltwithoutpermitswhen,infact,morethan15% ofthestructureswerebuilt withoutpermits.
AnswerExplanation
Corectanswer:
AType Ierroristhedecisionnotorejecthenulhypothesiswhen,infact,itisfalse.In thiscase,theType Ierroriswhenthebuildinginspectorthinksthatnomore
than15% ofthestructureswerebuiltwithoutpermitswhen,infact,more than15% ofthestructureswerebuiltwithoutpermits.
Youranswer:
Content attribution- Opens a dialog
QUESTION4 1/1POINTS
Sup oseachefclaimsthathermeatbalweightislessthan4 ounces,onaverage. Severalofhercustomersdonotbelieveher,sothechefdecidestodoahypothesistest, ata10% significancelevel,topersuadethem.Sheco ks14 meatbals.Themean weightofthesamplemeatbalsis3.7 ounces.Thechefknowsfrom experiencethathe standarddeviationforhermeatbalweightis0.5 ounces.
H0:μ≥4;Ha:μ<4
α=0.1 (significancelevel)
Whatistheteststatistic(z-score)ofthisone-meanhypothesistest,roundedtotwo decimalplaces?
AnswerExplanation
Corectanswers:
Thehypotheseswerechosen,andthesignificancelevelwasdecidedon,sothenext stepinhypothesistestingistocomputetheteststatistic.Inthisscenario,thesample meanweight,x¯=3.7.Thesamplethechefusesis14 meatbals,son=14.She
knowsthestandarddeviationofthemeatbals,σ=0.5.Lastly,thechefiscomparing
thepopulationmeanweighto4 ounces.So,thisvalue(foundinthenulandalternative
hypotheses)isμ0.Nowwewilsubstitutethevaluesintotheformulatocomputethe teststatistic:
z0=x¯−μ0σn√=3.7−40.514√≈−0.30.134≈−2.24
So,theteststatisticforthishypothesistestisz0=−2.24.
QUESTION5 1/1POINTS
Whatisthep-valueofaright-tailedone-meanhypothesistest,withateststatistic ofz0=1.74?(Donotroundyouranswer;computeyouranswerusingavaluefrom the tablebelow.) z1.51.61.71.81.90.000.9330.9450.9550.9640.9710.010.9340. 9460.9560.9650.9720.020.9360.9470.9570.9660.9730.030.9
370.9480.9580.9660.9730.040.9380.9490.9590.9670.9740.0
50.9390.9510.9600.9680.9740.060.9410.9520.9610.9690.97
50.070.9420.9530.9620.9690.9760.080.9430.9540.9620.970
0.9760.090.9440.9540.9630.9710.977
AnswerExplanation
Corectanswers:
Thep-valueistheprobabilityofanobservedvalueofz=1.74 orgreaterifthenul hypothesisistrue,becausethishypothesistestisright-tailed.Thisprobabilityisequalto theareaundertheStandardNormalcurvetotherightofz=1.74.
Astandardnormalcurvewithtwopointslabeledonthehorizontalaxis.Themeanis labeledat0.0 andanobservedvalueof1.74islabeled.Theareaunderthecurveand totherightoftheobservedvalueisshaded.
UsingtheStandardNormalTable,wecanse thathep-valueisequalto0.959, whichistheareatotheleftofz=1.74.(StandardNormalTablesgiveareastothe left.)So,thep-valuewe'relo kingforisp=1−0.959=0.041.
QUESTION6 1/1POINTS
Ken eth,acompetitorincupstacking,claimsthathisaveragestackingtime
is8.2 seconds.Duringapracticesession,Ken ethhasasamplestackingtimemean of7.8 secondsbasedon11 trials.Athe4% significancelevel,doesthedata providesufficientevidencetoconcludethatKen eth'smeanstackingtimeisless than8.2 seconds?Aceptorejecthehypothesisgiventhesampledatabelow.
H0:μ=8.2 seconds;Ha:μ<8.2 seconds
α=0.04 (significancelevel)
z0=−1.75
p=0.0401
Donotrejecthenulhypothesisbecausethep-value0.0401 isgreaterthanthe significancelevelα=0.04.
Rejecthenulhypothesisbecausethep-value0.0401 isgreaterthanthesignificance levelα=0.04.
Rejecthenulhypothesisbecausethevalueofz isnegative. Rejecthenulhypothesisbecause|−1.75|>0.04.
Donotrejecthenulhypothesisbecause|−1.75|>0.04.
AnswerExplanation
Corectanswer:
InmakingthedecisiontorejectornotrejectH0,ifα>p-value,rejectH0 becausethe resultsofthesampledataaresignificant.Thereissufficientevidencetoconclude thatH0 isanincorrectbeliefandthathealternativehypothesis,Ha,maybecorrect. Ifα≤p-value,donotrejectH0.Theresultsofthesampledataarenotsignificant,so thereisnotsufficientevidencetoconcludethathealternativehypothesis,Ha,maybe correct.Inthiscase,α=0.04 islessthanorequaltop=0.0401,sothedecisionis tonotrejecthenulhypothesis.
QUESTION7 1/1POINTS
Arecentstudysugestedthat81% ofseniorcitizenstakeatleastoneprescription medication.Ameliaisanurseatalargehospitalwhowouldliketoknowwhetherthe percentageisthesameforseniorcitizenpatientswhogotoherhospital.Sherandomly selects59 seniorcitizenspatientswhoweretreatedathehospitalandfindsthat49 of
them takeatleastoneprescriptionmedication.Whatarethenulandalternative hypothesesforthishypothesistest?
{H0:p=0.81Ha:p>0.81
{H0:p≠0.81Ha:p=0.81
{H0:p=0.81Ha:p<0.81
{H0:p=0.81Ha:p≠0.81
AnswerExplanation
Corectanswer:
{H0:p=0.81Ha:p≠0.81
Firstverifywhetheraloftheconditionshavebe nmet.Letp bethepopulation proportionfortheseniorcitizenpatientstreatedatAmelia'shospitalwhotakeatleast oneprescriptionmedication.
Sincetherearetwoindependentoutcomesforeachtrial,theproportionfolowsa binomialmodel.
Thequestionstatesthathesamplewascolectedrandomly. 3.Theexpectednumberofsucesses,np=47.79,andtheexpectednumberof
failures,nq=n(1−p)=11.21,arebothgreaterthanorequalto5.
SinceAmeliaistestingwhethertheproportionisthesame,thenulhypothesisis thatp isequalto0.81 andthealternativehypothesisisthatp isnotequalto0.81. Thenulandalternativehypothesesareshownbelow.
{H0:p=0.81Ha:p≠0.81
QUESTION8 1/1POINTS
Aresearcherclaimsthatheproportionofcarswithmanualtransmissionisless than10%.Totesthisclaim,asurveychecked1000 randomlyselectedcars.Of thosecars,95 hadamanualtransmission.
Thefolowingisthesetupforthehypothesistest:
{H0:p=0.10Ha:p<0.10
Findtheteststatisticforthishypothesistestforaproportion.Roundyouranswer to2 decimalplaces.
AnswerExplanation
Corectanswers:
Theproportionofsucessesisp^=951000=0.095. Theteststatisticiscalculatedasfolows:
z=p^−p0p0⋅(1−p0)n−−−−−−√ z=0.095−0.100.10⋅(1−0.10)1000−−−−−−−−√ z≈−0.53
QUESTION9 1/1POINTS
Amedicalresearcherclaimsthatheproportionofpeopletakingacertainmedication thatdevelopserioussideeffectsis12%.Totesthisclaim,arandom sampleof90 peopletakingthemedicationistakenanditisdeterminedthat93peoplehave experiencedserioussideeffects.
Thefolowingisthesetupforthishypothesistest:
H0:p=0.12
Ha:p≠ 0.12
Findthep-valueforthishypothesistestforaproportionandroundyouranswerto3 decimalplaces.
ThefolowingtablecanbeutilizedwhichprovidesareasundertheStandardNormal Curve:
z 0.00 0.01 0.02 0.03 0.04 0.05 0.06 0.07 0.08 0.09
-1.8 0.036 0.035 0.034 0.034 0.033 0.032 0.031 0.031 0.030 0.029
-1.7 0.045 0.044 0.043 0.042 0.041 0.040 0.039 0.038 0.038 0.037
-1.6 0.055 0.054 0.053 0.052 0.051 0.049 0.048 0.047 0.046 0.046
-1.5 0.067 0.066 0.064 0.063 0.062 0.061 0.059 0.058 0.057 0.056
-1.4 0.081 0.079 0.078 0.076 0.075 0.074 0.072 0.071 0.069 0.068
AnswerExplanation
Corectanswers:
Herearethestepsne dedtocalculatethep-valueforahypothesistestforaproportion:
1.Determineifthehypothesistestisleftailed,rightailed,ortwotailed. 2.Computethevalueoftheteststatistic.
3.Ifthehypothesistestisleftailed,thep-valuewilbetheareaunderthestandard normalcurvetotheleftoftheteststatisticz0
Ifthetestisrightailed,thep-valuewilbetheareaunderthestandardnormal curvetotherightoftheteststatisticz0
Ifthetestistwotailed,thep-valuewilbetheareatotheleftof−|z0|plusthe areatotherightof|z0|underthestandardnormalcurve
Forthisexample,thetestisatwotailedtestandtheteststatistic,roundingtotwo decimalplaces,isz=0.1033−0.120.12(1−0.12)900−−−−−−−−−
−−−√≈−1.54.
Thusthep-valueistheareaundertheStandardNormalcurvetotheleftofaz-scoreof
-1.54,plustheareaundertheStandardNormalcurvetotherightofaz-scoreof1.54.
z 0.00 0.01 0.02 0.03 0.04 0.05 0.06 0.07 0.08 0.09
-1.8 0.036 0.035 0.034 0.034 0.033 0.032 0.031 0.031 0.030 0.029
-1.7 0.045 0.044 0.043 0.042 0.041 0.040 0.039 0.038 0.038 0.037
-1.6 0.055 0.054 0.053 0.052 0.051 0.049 0.048 0.047 0.046 0.046
-1.5 0.067 0.066 0.064 0.063 0.062 0.061 0.059 0.058 0.057 0.056
-1.4 0.081 0.079 0.078 0.076 0.075 0.074 0.072 0.071 0.069 0.068
From alo kuptableoftheareaundertheStandardNormalcurve,thecoresponding areaisthen2(0.062)=0.124.
QUESTION10 1/1POINTS
Aneconomistclaimsthatheproportionofpeoplewhoplantopurchaseafulyelectric vehicleastheirnextcarisgreaterthan65%.
Totesthisclaim,arandom sampleof750 peopleareaskediftheyplantopurchasea fulyelectricvehicleastheirnextcar Ofthese750 people,513 indicatethatheydo plantopurchaseanelectricvehicle.
Thefolowingisthesetupforthishypothesistest:
H0:p=0.65 Ha:p>0.65
Inthisexample,thep-valuewasdeterminedtobe0.026.
Cometoaconclusionandinterpretheresultsforthishypothesistestforaproportion (useasignificancelevelof5%.)
ThedecisionistorejectheNulHypothesis. Theconclusionisthathereisenoughevidencetosup ortheclaim.
ThedecisionistofailtorejectheNulHypothesis. Theconclusionisthathereisnotenoughevidencetosup ortheclaim.
AnswerExplanation
Corectanswer:
Tocometoaconclusionandinterpretheresultsforahypothesistestforproportion usingtheP-ValueAp roach,thefirststepistocomparethep-valuefrom thesample datawiththelevelofsignificance.
Thedecisioncriteriaisthenasfolows:
Ifthep-valueislessthanorequaltothegivensignificancelevel,thenthenul hypothesisshouldberejected.
So,ifp≤α,rejectH0;otherwisefailtorejectH0.
Whenwehavemadeadecisionabouthenulhypothesis,itisimportantowritea thoughtfulconclusionabouthehypothesesintermsofthegivenproblem'sscenario.
Assumingtheclaim isthenulhypothesis,theconclusionisthenoneofthefolowing:
ifthedecisionistorejecthenulhypothesis,thentheconclusionisthathereis enoughevidencetorejectheclaim.
ifthedecisionistofailtorejecthenulhypothesis,thentheconclusionisthat thereisnotenoughevidencetorejectheclaim.
Assumingtheclaim isthealternativehypothesis,theconclusionisthenoneofthe folowing:
ifthedecisionistorejecthenulhypothesis,thentheconclusionisthathereis enoughevidencetosup ortheclaim.
ifthedecisionistofailtorejecthenulhypothesis,thentheconclusionisthat thereisnotenoughevidencetosup ortheclaim.
Inthisexample,thep-value=0.026.Wethencomparethep-valuetothelevelof significancetocometoaconclusionforthehypothesistest.
Inthisexample,thep-valueislessthanthelevelofsignificancewhichis0.05.
Sincethep-valueisgreaterthanthelevelofsignificance,theconclusionistorejecthe nulhypothesis.
QUESTION1 1/1POINTS
Becky'sstatisticsteacherwasteachingtheclasshowtoperform thez-testfora proportion.Beckywasboredbecauseshehadalreadymasteredthetest,soshe decidedtose ifthecoinshehadinherpocketwouldcomeupheadsortailsinatruly random fashionwhenflip ed.Shediscretelyflip edthecoin30 timesandgot heads18 times.
Beckyconductsaone-proportionhypothesistestathe5% significancelevel,totest whetherthetrueproportionofheadsisdifferentfrom 50%.
Whichanswerchoiceshowsthecorrectnulandalternativehypothesesforthistest?
H0:p=0.6;Ha:p>0.6,whichisaright-tailedtest. H0:p=0.5;Ha:p<0.5,whichisaleft-tailedtest. H0:p=0.6;Ha:p≠0.6,whichisatwo-tailedtest.
H0:p=0.5;Ha:p≠0.5,whichisatwo-tailedtest.
AnswerExplanation
Corectanswer:
H0:p=0.5;Ha:p≠0.5,whichisatwo-tailedtest.
Thenulhypothesisshouldbetrueproportion:H0:p=0.5.Beckywantstoknowif thetrueproportionofheadsisdifferentfrom 0.5.Thismeansthatwejustwantotestif theproportionisnot0.5.So,thealternativehypothesisisHa:p≠0.5,whichisatwo- tailedtest.
QUESTION12 1/1POINTS
Johnownsacomputerepairservice.Foreachcomputer,he
charges$50 plus$45 perhourofwork.Alinearequationthatexpressesthetotal amountofmoneyJohnearnspercomputerisy=50+45x.Whatarethe independentanddependentvariables?Whatisthey-interceptandtheslope?
Theindependentvariable(x)istheamountoftimeJohnfixesacomputer.The dependentvariable(y)istheamount,indolars,Johnearnsforacomputer.
Johnchargesaone-timefe of$50 (thisiswhenx=0),sothey-interceptis50.John earns$45 foreachhourheworks,sotheslopeis45.
Theindependentvariable(x)istheamount,indolars,Johnearnsforacomputer.The dependentvariable(y)istheamountoftimeJohnfixesacomputer.
Johnchargesaone-timefe of$45 (thisiswhenx=0),sothey-interceptis45.John earns$50 foreachhourheworks,sotheslopeis50.
Theindependentvariable(x)istheamount,indolars,Johnearnsforacomputer.The dependentvariable(y)istheamountoftimeJohnfixesacomputer.
Johnchargesaone-timefe of$50 (thisiswhenx=0),sothey-interceptis50.John earns$45 foreachhourheworks,sotheslopeis45.
Theindependentvariable(x)istheamountoftimeJohnfixesacomputer.The dependentvariable(y)istheamount,indolars,Johnearnsforacomputer.
Johnchargesaone-timefe of$45 (thisiswhenx=0),sothey-interceptis45.John earns$50 foreachhourheworks,sotheslopeis50.
AnswerExplanation
Corectanswer:
Theindependentvariable(x)istheamountoftimeJohnfixesacomputerbecauseitis thevaluethatchanges.Hemayworkdifferentamountspercomputer,andhisearnings aredependentonhowmanyhoursheworks.Thisiswhytheamount,indolars,John earnsforacomputeristhedependentvariable(y).
They-interceptis50 (b=50).Thisishisone-timefe.Theslopeis45 (a=45). Thisistheincreaseforeachhourheworks.
QUESTION13 1/1POINTS
Arianake pstrackoftheamountoftimeshestudiesandthescoreshegetsonher quizzes.Thedataareshowninthetablebelow.Whichofthescaterplotsbelow acuratelyrecordsthedata?
Hoursstudying Quizscore
1 5
2 5
3 7
4 9
5 9
AscaterplothasahorizontalaxislabeledHoursstudyingfrom 0to6inincrementsof1 andaverticalaxislabeledQuizscorefrom 0to10inincrementsof2.Thefolowing pointsareploted:left-parenthesis1comma5right-parentheses;left-parenthesis2 comma5right-parentheses;left-parenthesis3comma7right-parentheses;left- parenthesis4comma9right-parentheses;left-parenthesis5comma9right- parentheses.Alvaluesareap roximate.
AscaterplothasahorizontalaxislabeledHoursstudyingfrom 0to10inincrementsof 2andaverticalaxislabeledQuizscorefrom 0to6inincrementsof1.Thefolowing pointsareploted:left-parenthesis5comma1right-parentheses;left-parenthesis5 comma2right-parentheses;left-parenthesis7comma3right-parentheses;left- parenthesis9comma4right-parentheses;left-parenthesis9comma5right- parentheses.Alvaluesareap roximate.
AscaterplothasahorizontalaxislabeledHoursstudyingfrom 0to6inincrementsof1 andaverticalaxislabeledQuizscorefrom 0to9inincrementsof1.Thefolowing pointsareploted:left-parenthesis1comma5right-parentheses;left-parenthesis2 comma5right-parentheses;left-parenthesis3comma7right-parentheses;left- parenthesis4comma8right-parentheses;left-parenthesis5comma8right- parentheses.
AscaterplothasahorizontalaxislabeledHoursstudyingfrom 0to6inincrementsof1 andaverticalaxislabeledQuizscorefrom 0to12inincrementsof2.Thefolowing pointsareploted:left-parenthesis1comma5right-parentheses;left-parenthesis2 comma5right-parentheses;left-parenthesis3comma8right-parentheses;left- parenthesis4comma8right-parentheses;left-parenthesis5comma1 right- parentheses.Alvaluesareap roximate.
AnswerExplanation
Corectanswer:
Thevaluesforhoursstudyingcorrespondtox-values,andthevaluesforquizscore correspondtoy-values.Eachrowofthetableofdatacorespondstoa
point(x,y) plotedinthescaterplot.Forexample,thefirstrow,1,5,correspondsto thepoint(1,5).Doingthisforeveryrowinthetable,wefindthescaterplotshould havepoints(1,5),(2,5),(3,7),(4,9),and(5,9).
QUESTION14 1/1POINTS
Dataiscolectedontherelationshipbetwe ntimespentplayingvideogamesandtime spentwithfamily.Thedataisshowninthetableandthelineofbestfitforthedata isy^=−0.27x+57.5.Assumethelineofbestfitissignificantandthereisa stronglinearelationshipbetwe nthevariables.
Video Games (Minutes) 306090120 Time with Family (Minute s) 50403525
Acordingtothelineofbestfit,thepredictednumberofminutesspentwithfamilyfor someonewhospent95 minutesplayingvideogamesis31.85.Isitreasonableto usethislineofbestfitomaketheaboveprediction?
Theestimate,apredictedtimeof31.85 minutes,isunreliablebutreasonable. Theestimate,apredictedtimeof31.85 minutes,isbothunreliableandunreasonable. Theestimate,apredictedtimeof31.85 minutes,isbothreliableandreasonable.
Theestimate,apredictedtimeof31.85 minutes,isreliablebutunreasonable.
AnswerExplanation
Corectanswer:
Theestimate,apredictedtimeof31.85 minutes,isbothreliableandreasonable.
Thedatainthetableonlyincludesvideogametimesbetwe n30 and120 minutes, sothelineofbestfitgivesreasonablepredictionsforvalues
ofx betwe n30 and120.Since95 isbetwe nthesevalues,theestimateisboth
reliableandreasonable.
QUESTION15 0/1POINTS
Whichofthefolowingarefeasibleequationsofaleastsquaresregressionlineforthe an ualpopulationchangeofasmalcountryfrom theyear2000 totheyear2015? Selectalthatap ly.
•
yˆ=38,000+2500x
•
•
yˆ=38,000−3500x
•
•
yˆ=−38,000+2500x
•
•
yˆ=38,000−1500x
•
AnswerExplanation
Corectanswer:
Populationchangecanbepositiveornegative,anditcanincreaseordecrease.Based onthegiveninformation,therearenopracticalimitstopopulationchange,although therearelimitssuchasthedecreaseinpopulationcan otexce dthecurentpopulation (asitwouldleaveanegativenumberofpeopleinthecountry),ortheincreasein populationcouldbelimitedbyothereal-worldfactors(suchaslackofspaceorlegal immigrationlimits).
Youranswer:
yˆ=38,000+2500x
QUESTION17 1/1POINTS
Anamateurastronomerisresearchingstatisticalpropertiesofknownstarsusinga varietyofdatabases.Theycolecthecolorindex,orB−V index,anddistance(inlight years)from Earthfor30 stars.Thecolorindexofastaristhedifferenceinthelight absorptionmeasuredfrom thestarusingtwodifferentlightfilters(aBandaVfilter).
Thisthenalowsthescientistoknowthestar'stemperatureandanegativevalue meansahotbluestar.Alightyearisthedistancelightcantravelin1 year,whichis ap roximately5.9 trilionmiles.Thedataisprovidedbelow.UseExceltocalculatethe correlationcoefficientr betwe nthetwodatasets,roundingtotwodecimalplaces.
B-Vindex
Distance(ly)
1.1
1380
0.4
5 6
1.0
7 1
0.5
304
1.4
532
1.0
751
0.5
267
0.8
2 9
0.5
5 2
HelpCopytoClipboardDownloadCSV
Thatiscorect!
AnswerExplanation
Corectanswers:
ThecorelationcoefficientcanbecalculatedeasilywithExcelusingthebuilt-in CORRELfunction.
OpentheacompanyingdatasetinExcel.
Inanopencel,type"=CORREL(A2:A31,B2:B31)",andthenhitENTER.
Youcouldlabeltheresultofthiscelbywriting"Correlationcoefficient"or"r"inan adjacentopencel.
Thecorelationcoefficient,roundedtotwodecimalplaces,isr≈0.18.
QUESTION18 0/1POINTS
Theweightofacarcaninfluencethemileagethathecarcanobtain.Arandom sample of20 cars’weightsandmileageiscolected.Thetablefortheweightandmileageof thecarsisgivenbelow.UseExceltofindthebestfitlinearegressionequation,where weightistheexplanatoryvariable.Roundtheslopeandinterceptothre decimal
places.
30.0
32.2
20.0
56.0
20.0
46.2
45.0
19.5
40.0
23.6
45.0
16.7
25.0
42.2
5 .0
13.2
17.5
65.4
HelpCopytoClipboardDownloadCSV
That'snotright.
y=$$1.181 x+$$71.374
AnswerExplanation
y= $$ x+ $$
Corectanswers:
Tofindthebestfitforthegivendata,useExcel.
OpenExcel.EnterthevaluesofweightincolumnAandmileageincolumnB. Highlightalthecelscontainingthedata.
From theInsertab,selectScater.UseScaterwithonlyMarkers,thefirstypeof scaterchart.Asimpleplotisshown.
Toad thelinearfitothegraph,clickanywhereinsidethegrapharea.Select theLayouttabfrom theChartTo ls.ClickontheTrendlineiconandselectheLinear Trendlineoption.Thelineofbestfitisad edtothegraph.
Fortheequationofthelineofbestfit,clickonTrendlineandselectMoreTrendline Options ..
ChecktheDisplayEquationonchartbox.Theequationoflineofbestfitisshown onthegraph.
Tochangethenumberofdecimalplacesinthetrendlineequation,right-clickonthe equationforthetrendlineandselectFormatTrendlineLabel..
SelectNumberunderCategory,changethenumberofdecimalplacesto3,and clickClose.Thus,theequationoflineofbestfitwithslopeandinterceptroundedto thre decimalplacesisyˆ=−1.181x+71.374.
QUESTION19 1/1POINTS
Afarmerdividedhispieceoflandinto4 equivalentgroups.Thequalityofthesoilisthe sameacrossthe4 groupsofland.Heplantedthesamecropinal4 groupsoflandand recordedtheyieldofthecropinal4 groupsfora4 we kperiod.Isthestudy observationalorexperimental?Ifitisanexperiment,whatisthecontroledfactor?
Thestudyisanobservationalstudy.
Thestudyisanexperiment.Thecontroledfactoristhe4 we kobservationperiod. Thestudyisanexperiment.Thecontroledfactoristheland.
Thestudyisanexperiment.Thecontroledfactoristhegrowthofthecrops.
AnswerExplanation
Corectanswer:
Thestudyisanobservationalstudy.
Thesamplesarechosenusinganap ropriateprocess;however,noatemptismadeto controlanyaspectofthesampleeventhoughthevariablesofinterestarerecordedfor eachgroup.
QUESTION20 1/1POINTS
Totestheeffectivenessofadrugproposedtorelievesymptomsofheadache, physiciansincludedparticipantsforastudy.Theygavethedrugtoonegroupandadrug withnotherapeuticeffectoanothergroup.Whichgroupreceivestheplacebo?
thephysicians thegroupthatreceivedthedrugforheadache thegroupthatreceivedthedrugwithnotherapeuticeffect
alofthepeopleinthestudy
AnswerExplanation
Corectanswer:
thegroupthatreceivedthedrugwithnotherapeuticeffect
Whentheexperimentalunitsarepeople,ap lyingtreatmentsthatshouldbeinertcan actualyhaveeffects.Inthisstudy,thedrugwithnotherapeuticeffectsistheplacebo,so thegroupthatreceivesthatdrugreceivestheplacebo.
QUESTION21 1/1POINTS
Adoctornotesherpatient'stemperatureindegre sFahrenheiteveryhourtomakesure thepatientdoesnotgetafever.Whatisthelevelofmeasurementofthedata?
nominal
ordinal
interval ratio
AnswerExplanation
Corectanswer:
interval Thisisintervaldatabecausedegre sFahrenheitisanumericalscalewheredifferences aremeaningful.However,becauseFahrenheitdoesnothaveatruezerovalue,itisnot ratiodata.
QUESTION2 0/1POINTS
Asamemberofamarketingteam,youhavebe ntaskedwithdeterminingthenumber ofDVDsthatpeoplehaverentedoverthepastsixmonths.Yousampletwentyadults anddecidethathebestdisplayofdataisafrequencytableforgroupeddata.Construct thistableusingfourclasses.
15,31,28,19,14,18,28,19,10,19,10,24,14,18,24,27,10,18,16,2
3
AnswerExplanation
Corectanswers:
Notethathedataisnotorderedandthatwehavebe naskedtouse4classes.
Todeterminetheclasswidth,usetheformula:Max Value−Min ValueNumber of Classes=31−104=5.25.Sincethisvalueisnotaninteger,roundto6.
Usetheminimum value,10,forthelowerclasslimitofthefirstclass.Tofindalother lowerclasslimits,ad theclasswidth,6. Forexample,thesecondlowerclasslimit wouldbe:10+6=16.
Lower Class Limit Upper Class Limit Frequency
10
16
22
28
Tofindtheup erclasslimits,ad theclasswidthminus1,toeachlowerclasslimit.For example,theup erclasslimitofthefirstclasswouldbe:10+5=15.
Lower Class Limit Upper Class Limit Frequency
10 15
16 21
22 27
28 33
Tofindthefrequencyforeachclass,counthenumberofdatavaluesthatfalwithinthe rangeofeachclass.Forexample,thedatavalues15,14,10,10,14,and10falwithin therangeofthefirstclass,10-15.So,thefrequencyofthisclassis6.
QUESTION23 1/1POINTS
Thehistogram belowdisplaystheweightsofrainbowtrout(inpounds)caughtbyal visitorsatalakeonaSaturdayafterno n.Acordingtothishistogram,whichrangeof weights(inpounds)containsthelowestfrequency?
Ahistogram hasaverticalaxislabeledFrequencyandhasahorizontalaxisthat measuressixcategoriesofrainbowtroutweight(inpounds).Readingfrom left-to-right, theweightandfrequencyofeachcategoryare:4.5to6.5hasfrequencyof4,6.5to8.5 hasfrequency5,8.5to10.5hasfrequency7,10.5to12.5hasfrequency3,12.5to14.5 hasfrequency1,14.5to16.5hasfrequency2.
AnswerExplanation
Corectanswers:
Therange12.5−14.5 hasthelowestbarinthehistogram,whichmeansthathis rangeofvaluesalsohasthelowestfrequency.Therefore,1 visitorcaughtarainbow trouthatweighedgreaterthan12.5 butlessthan14.5 pounds.
QUESTION24 1/1POINTS
Describetheshapeofthegivenhistogram.
Ahistogram hasahorizontalaxisfrom 0to16inincrementsof2andaverticalaxis labeledFrequencyfrom 0to10inincrementsof2.Thehistogram containsverticalbars ofwidth1startingathehorizontalaxisvalue0.Theheightsofthebarsareasfolows, wherethelefthorizontalaxislabelislistedfirstandthefrequencyislistedsecond:0,0; 1,0;2,6;3,6;4,7;5,6;6,6;7,6;8,7;9,6;10,6;1 ,6;12,6;13,7;14,0;15,0.
uniform unimodalandsymmetric unimodalandleft-skewed unimodalandright-skewed
bimodal
AnswerExplanation
Corectanswer:
uniform Althebarsinauniform histogram areabouthesameheight.
QUESTION25 1/1POINTS
Thebargraphbelowshowsthenumberofboysandgirlsindifferentclasses.
AbargraphhasahorizontalaxislabeledClassesandaverticalaxislabeledStudents from 0to16inincrementsof2.Therearetwoverticalbarsaboveeachhorizontalaxis label,withthebarontheleftrepresentingBoysandthebarontherightrepresenting Girls.Thebarshaveheightsasfolows,withthehorizontalaxislabelistedfirstandthe barheightslistedsecondfrom leftoright:Mrs.Brown,10and15;Ms.James,1 and 12.
HowmanytotalstudentsareinMs.James'sclass?Donotincludetheunitsinyour
answer.
AnswerExplanation
Corectanswers:
TofindthenumberofstudentsinMs.James'sclass,findtheheightsofthebarsforthat classandad them.Inthiscase,wefinditis11+12=23.
QUESTION26 0/1POINTS
ThelinegraphshownbelowrepresentsthenumberofTVsinahousebysquare fo tage(inhundredsofet).Acordingtotheinformationabove,whichofthefolowing isanap ropriateanalysisofsquarefo tageandTVs?
Alinegraphhasanx-axislabeledSquareFo tage(inhundredsofet)inincrementsof one,anday-axislabeledNumberofTV'sinincrementsofone.Begin ingathepoint startparentheses6,2endparentheses,alineincreasestothepointstartparentheses 8.5,3endparentheses.Thelineremainsconstantothepointstartparentheses10,3 endparentheses.Thelinethenincreases,passingthroughthepointstartparentheses 12,5end parenthesesandcontinuesincreasinguntilitreachesthepointstart parentheses16,6endparentheses.
From thedata,thenumberofTVsdoubledfrom asquarefotageof8.5 and10. From thedata,thereisasteadydecreaseinthesquarefotageandnumberofTVs. From thedata,thereisasteadyincreaseinthesquarefo tageandnumberofTVs.
From thedata,whenthesquarefo tageisbetwe n8.5 and10,thenumberofTVs remainsthesame.
AnswerExplanation
Corectanswer:
Giventhelinegraph,atasquarefotageof8.5,thenumberofTVsis3.Atasquare fo tageof10,thenumberofTVsisalso3.Therefore,whenthesquarefo tageis betwe n8.5 and10,thenumberofTVsremainsthesame.
Youranswer:
From thedata,thereisasteadyincreaseinthesquarefo tageandnumberofTVs.
Thisresponseisnotcorrect.Whilemostofthelineisincreasing,thenumberofTVs remainsthesamebetwe nasquarefo tageof8.5 and10.
QUESTION27 1/1POINTS
Aliceselsboxesofcandyathebasebalgameandwantstoknowthemeannumberof boxesshesels.Thenumbersforthegamessofararelistedbelow.
16,14,14,21,15
Findthemeanboxessold.
AnswerExplanation
Corectanswers:
Rememberthathemeanisthesum ofthenumbersdividedbythenumberof numbers.Thereare5 numbersinthelist.Sowefindthathemeanboxessoldis
QUESTION28 1/1POINTS
Giventhefolowinglistofprices(inthousandsofdolars)ofrandomlyselectedtrucksat acardealership,findthemedian.
20,46,19,14,42,26,33
AnswerExplanation
Corectanswers:
Ithelpstoputhenumbersinorder.
14,19,20,26,33,42,46
Now,becausethelisthaslength7,whichisod,weknowthemediannumberwilbe themid lenumber.Inotherwords,wecancountoitem 4 inthelist,whichis26.So themedianprice(inthousandsofdolars)ofrandomlyselectedtrucksatacar dealershipis26.
QUESTION29 1/1POINTS
Eachpersoninagroupshufflesadeckofcardsandke psselectingacarduntila que nap ears.Findthemodeofthefolowingnumberofcardsdrawnfrom adeckuntil aque nap ears.
3,12,3,11,5,5,3,10,12
AnswerExplanation
Corectanswers:
Ifwecounthenumberoftimeseachvalueap earsinthelist,wegethefolowing frequencytable:
Value Frequency
3 3
5 2
10 1
11 1
12 2
Notethat3 ocurs3 times,whichisthegreatestfrequency,so3 isthemodeofthe numberofcardsdrawnfrom adeckuntilaque nap ears.
QUESTION30 1/1POINTS
Giventhefolowinghistogram,decideifthedataisskewedorsymmetrical.
AbargraphhasahorizontalaxistitledValueslabeledfrom 2to18inincrementsof2 andaverticalaxistitledFrequencylabeledfrom 0to20 inincrementsof50.14bars areploted,abovethenumbers2to16.From leftoright,theheightsofthebarsareas folows:1.5.10.40,75,125,190,180,130,125,60,25,20,10.Alvaluesare
ap roximate.
Thedataareskewedtotheleft.
Thedataareskewedtotheright. Thedataaresymmetric.
AnswerExplanation
Corectanswer:
Thedataaresymmetric. Notethathehistogram ap earstoberoughlysymmetric.Sothedataaresymmetric.
QUESTION31 1/1POINTS
Whichofthedatasetsrepresentedbythefolowingboxandwhiskerplotshasthe smaleststandarddeviation?
Fourhorizontalbox-and-whiskerplotsshareaverticalaxiswiththeclassesD,C,B,and Aandahorizontalaxisfrom 0to120inincrementsof20.Thebox-and-whiskerplot abovetheclasslabelAhasthefolowingfive-numbersummary:4 ,69,7 ,82,and1 2.
Thebox-and-whiskerplotabovetheclasslabelBhasthefolowingfive-number summary:19,64,78,87,and121.Thebox-and-whiskerplotabovetheclasslabelC hasthefolowingfive-numbersummary:60,72,75,80,and92.Thebox-and-whisker
plotabovetheclasslabelDhasthefolowingfive-numbersummary:2,63,7 ,92,and
138.Alvaluesareap roximate.
A B C
D
AnswerExplanation
Corectanswer:
C
Rememberthathestandarddeviationisameasureofhowspreadouthedatais.Ifthe valuesareconcentratedaroundthemean,thenadatasethasalowerstandard deviation.
Aboxandwhiskerplotwithshortwhiskersandashortboxhasvaluesthatareless spreadout,andhencehasasmalerstandarddeviation.
QUESTION32 1/1POINTS
Thegraphbelowshowsthegraphsofseveralnormaldistributions,labeledA,B,andC, onthesameaxis.Determinewhichnormaldistributionhasthesmaleststandard deviation.
Afigureconsistsofthre curvesalongahorizontalaxis,labeledUp erA,Up erBand Up erC.CurveUp erAisshortandthemostspreadout,curveUp erBistalandthe leastspreadout,andcurveCisfarthertothelefthanA.
A
B C
AnswerExplanation
Corectanswer:
B
Rememberthathestandarddeviationtelshowspreadouthenormaldistributionis.So ahighstandarddeviationmeansthegraphwilbeshortandspreadout.Alowstandard deviationmeansthegraphwilbetalandskiny.
ThedistributionthatisthetalestandleastspreadoutisB,sothathasthesmalest standarddeviation.
QUESTION3
1/1POINTS
Braydentossesacoin500 times.Ofthose500 times,heobservesheadsatotal of416 times.Calculationsshowthatheprobabilityofthisocurringbychanceisless than0.01,assumingthecoinisfair.Determinethemeaningofthesignificancelevel.
Weexpecthat416 ofevery500 cointosseswilresultinheads. Athe0.01 levelofsignificance,thecoinislikelynotafaircoin. Thereiscertaintythathecoinisnotafaircoin.
Theresultsarenotstatisticalysignificantathe0.05 levelofsignificance.
AnswerExplanation
Corectanswer:
Athe0.01 levelofsignificance,thecoinislikelynotafaircoin.
Theresultsoftheexperimentaresignificantathe0.01 levelofsignificance.This meanstheprobabilitythatheoutcomewastheresultofchanceis0.01 orless. Becauseofthis,wecanbefairlyconfident,butnotcertain,thathecoinisnotafair
coin.
QUESTION34 1/1POINTS
Isthestatementbelowtrueorfalse?
Independentisthepropertyoftwoeventsinwhichtheknowledgethatoneoftheevents ocurreddoesnotaffecthechancetheotherocurs.
True
False
AnswerExplanation
Corectanswer:
True Independentisdefinedasthepropertyoftwoeventsinwhichtheknowledgethatoneof theeventsocurreddoesnotaffecthechancetheotherocurs.
QUESTION35 1/1POINTS
Ofthefolowingpairsofevents,whichpairhasmutualyexclusiveevents?
rolingasum greaterthan7 from tworolsofastandarddieandrolinga4 forthefirst throw
drawinga2 anddrawinga4 withreplacementfrom astandarddeckofcards rolingasum of9 from tworolsofastandarddieandrolinga2 forthefirstrol
drawingaredcardandthendrawingablackcardwithreplacementfrom astandard deckofcards
AnswerExplanation
Corectanswer:
rolingasum of9 from tworolsofastandarddieandrolinga2 forthefirstrol
Mutualyexclusiveeventsareeventsthatcan otocurtogether.Inthiscase,rolinga sum of9 from tworolsofastandarddieandroling2 forthefirstrolaretwoevents thatcan otpossiblyocurtogether.
QUESTION36 1/1POINTS
Filinthefolowingcontingencytableandfindthenumberofstudentswhobothgotothe beachANDgotothemountains.
StudentsgotothebeachdonotgotothebeachTotalgotothemount ains48donotgotothemountains21Total3695
AnswerExplanation
Corectanswers:
Byusingtheknowntotalsalongtherowsandcolumnsyoucanfilintherestofthe contingencytable.Forexample,lo kingatherowoftotalsinthetable,weknowthat theunknownnumberplus48 is95,sothemissingnumbermustbe47.Continuingin thisway,wecanfilintheentiretable:
StudentsgotothebeachdonotgotothebeachTotalgotothemount ains103848donotgotothemountains262147Total365995
From this,wecanse thathenumberofstudentswhobothgotothebeachandgoto themountainsis10.
QUESTION37 1/1POINTS
Astatisticsprofessorecentlygradedfinalexamsforstudentsinherintroductory statisticscourse.Inareviewofhergrading,shefoundthemeanscoreout of100 pointswasax¯=77,withamarginoferrorof10.
Constructaconfidenceintervalforthemeanscore(outof100 points)onthefinal exam.
AnswerExplanation
Corectanswers:
Aconfidenceintervalisanintervalofvalues,centeredonapointestimate,oftheform
(pointestimate−marginof error,pointestimate+marginof error)
Usingthegivenpointestimateforthemean,x¯=77 andmarginoferror10,the confidenceintervalis:
(77−10,77+10)(67,87)
QUESTION38 1/1POINTS
Arandom sampleofadultswereaskedwhethertheyprefereadingane-bo kovera printedbo k.Thesurveyresultedinasampleproportionofp′=0.14,withasampling standarddeviationofσp′=0.02,whopreferredreadingane-bo k.
Usetheempiricalruletoconstructa95% confidenceintervalforthetrueproportionof adultswhoprefere-bo ks.
AnswerExplanation
Corectanswers:
BytheEmpiricalRule,a95% confidenceintervalcorrespondstoaz-scoreofz=2.
Substitutingthegivenvaluesp′=0.14 andσp′=0.02,aconfidenceintervalis
(p′−z⋅σp′,p′+z⋅σp′)(0.14−2⋅0.02,0.14+2⋅0.02) (0.14−0.04,0.14+0.04)(0.10,0.18)
QUESTION39 1/1POINTS
Thepopulationstandarddeviationfortheheightsofdogs,ininches,inacity is3.7 inches.Ifwewantobe95% confidenthathesamplemeanis
within2 inchesofthetruepopulationmean,whatistheminimum samplesizethatcan
betaken?
z0.101.282z0.051.645z0.0251.960z0.012.326z0.0052.576
Usethetableaboveforthez-score,andbesuretorounduptothenearestinteger.
AnswerExplanation
Corectanswers:
Theformulaforsamplesizeisn=z2σ2EBM2.Inthisformula,z=zα2=z0.025=1.96, becausetheconfidencelevelis95%.From theproblem,weknow
thatσ=3.7 andEBM=2.Therefore,n=z2σ2EBM2=(1.96)2(3.7)222≈13.15. Usen=14 toensurethathesamplesizeislargeenough.
Also,thesamplesizeformulashownaboveissometimeswritenusinganalternate formatofn=(zσE)2.Inthisformula,Eisusedtodenotemarginoferrorandtheentire parenthesesisraisedtotheexponent2.
Therefore,themarginoferrorforthemeancanbedenotedby"EBM"orby"E".Either formulaforthesamplesizecanbeusedandtheseformulasareconsideredas equivalent.
QUESTION40
·
0/1POINTS
Whichofthefolowingfrequencytablesshowaskeweddataset?Selectalanswersthat ap ly.
•
Value Frequency
5 1
6 2
7 10
8 11
9 17
10 17
11 15
12 12
13 7
14 7
15 0
16 1
•
•
Value Frequency
5 1
6 3
7 8
8 10
9 13
10 26
11 14
12 12
13 8
14 3
15 1
16 1
•
•
Value Frequency
12 1
13 1
14 3
15 6
16 23
17 29
18 19
19 15
20 3
•
•
Value Frequency
0 5
1 16
2 23
3 19
4 22
5 9
6 4
7 2
•
AnswerExplanation
Corectanswer:
Value Frequency
12 1
13 1
14 3
15 6
16 23
17 29
18 19
19 15
20 3
Value Frequency
0 5
1 16
2 23
3 19
4 22
5 9
6 4
7 2
Rememberthatdataareleftskewedifthereisamainconcentrationoflargevalueswith severalmuchsmalervalues.Similarly,rightskeweddatahaveamainconcentrationof smalvalueswithseveralmuchlargervalues.Wecanse thathefolowingisleft skewedbecauseoftheconcentrationoflargevalueswithmanysmalervalues:
Value Frequency
12 1
13 1
14 3
15 6
16 23
17 29
18 19
19 15
20 3
Andthefolowingisrightskewedbecauseofitsconcentrationofsmalvalueswithmany largervalues:
Value Frequency
0 5
1 16
2 23
3 19
4 22
5 9
6 4
7 2
Theotherfrequencytablesaremorebalancedandsymmetrical.
Youranswer:
Value Frequency
5 1
6 3
7 8
8 10
9 13
10 26
11 14
12 12
13 8
14 3
15 1
16 1
Thedatainthistableisroughlysymmetricalabout10.
Value Frequency
12 1
13 1
14 3
15 6
16 23
17 29
18 19
19 15
20 3
Correct!
QUESTION41 1/1POINTS
Apolwasconductedduringthefinalgameofthebasketbalseasontodetermine whetherfanswantedtose thedefendingchampionswinthegameorthechalenging team winthegame.From thepol,216 ofthe374 residentssampledfrom urban
areaswanthedefendingchampionstowinthegame.Inmoreruralareas,304 of
the466 residentspoledwanthedefendingchampionstowinthegame.Assuming
locationhasnothingtodowithteam preference,theprobabilitythathedatagathered wastheresultofchanceiscalculatedtobe0.03.Whatisthecorrectinterpretationof thiscalculation?
Morepeoplefrom ruralareaswanthedefendingchampionstowinthegame.
Exactly216 outofevery374 urbanresidentswanthedefendingchampionstowinthe game.
Theresultsarestatisticalysignificantathe0.05 levelofsignificanceinshowingthat theproportionofpeopleinruralareaswhowanthedefendingchampionstowinthe gameisdifferenthantheproportionofpeopleinurbanareas.
Thedataisnotstatisticalysignificantathe0.05 levelofsignificanceinshowingthat theproportionofpeopleinruralareaswhowanthedefendingchampionstowinthe gameisdifferenthantheproportionofpeopleinurbanareas.
AnswerExplanation
Corectanswer:
Theprobabilityvaluecalculatedis0.03.Thisislessthan0.05,soweconcludethat thedataarestatisticalysignificantinshowingthatheproportionofpeopleinruralareas whowanthedefendingchampionstowinthegameisdifferenthantheproportionof peopleinurbanareas.
QUESTION42 1/1POINTS
Inapsychologicalstudyaimedatestingadrugthatreducesanxiety,theresearcher groupedtheparticipantsinto2 groupsandgavetheanxiety-reductionpiltoonegroup andaninertpiltoanothergroup.Whichgroupreceivestheplacebo?
thegroupthatreceivedtheanxiety-reductionpil thepsychologicalstudy
althepeopleinthestudy
thegroupthatreceivedtheinertpil
AnswerExplanation
Corectanswer:
thegroupthatreceivedtheinertpil
Whentheexperimentalunitsarepeople,ap lyingtreatmentsthatshouldbeinertcan actualyhaveeffects.Sothegroupthatreceivedtheinertpilreceivedtheplacebo.
QUESTION43 1/1POINTS
Whichofthefolowingresultsinthenulhypothesisμ≥38 andalternative hypothesisμ<38?
Afitnesscenterclaimsthathemeanamountoftimethatapersonspendsathegym pervisitisatmost38 minutes.
Afitnesscenterclaimsthathemeanamountoftimethatapersonspendsathegym pervisitisfewerthan38 minutes.
Afitnesscenterclaimsthathemeanamountoftimethatapersonspendsathegym pervisitis38 minutes.
Afitnesscenterclaimsthathemeanamountoftimethatapersonspendsathegym pervisitismorethan38 minutes.
AnswerExplanation
Corectanswer:
Considereachoftheoptions.ThescenarioinoptionBhasthenul hypothesisμ≥38 basedonthewords"fewerthan"andthefacthathenul hypothesisisalwaysstatedwithsomeform ofequality.
QUESTION4
1/1POINTS
TrueorFalse:Themoreshoesamanufacturermakes,themoreshoestheysel.
True
False
AnswerExplanation
Corectanswer:
False
Insup lyanddemand,acompanydoesn'tmakeaproducthopingthatsomeonewil buythem,theyhaveaDemandfirstfortheirproductandthen,theyproducemoreof thatgivenproduct.
QUESTION45 1/1POINTS
Filinthefolowingcontingencytableandfindthenumberofstudentswhobothdonot playsportsANDdonotplayaninstrument.
StudentsplaysportsdonotplaysportsTotalplayaninstrument33d onotplayaninstrument69Total6267
AnswerExplanation
Corectanswers:
Byusingtheknowntotalsalongtherowsandcolumnsyoucanfilintherestofthe contingencytable.Forexample,lo kingathesecondrowinthetable,weknow that33 ad edtotheunknownnumberinthemid leis67,sothatunknownnumber
is34.Continuinginthisway,wecanfilintheentiretable:
StudentsplaysportsdonotplaysportsTotalplayaninstrument273 360donotplayaninstrument353469Total6267129
From this,wecanse thathenumberofstudentswhobothdonotplaysportsanddo notplayaninstrumentis34.
FEEDBACK
•
•
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•
Content attribution- Opens a dialog
QUESTION45 1/1POINTS
Filinthefolowingcontingencytableandfindthenumberofstudentswhobothdonot playsportsANDdonotplayaninstrument.
StudentsplaysportsdonotplaysportsTotalplayaninstrument33d onotplayaninstrument69Total6267
AnswerExplanation
Corectanswers:
Byusingtheknowntotalsalongtherowsandcolumnsyoucanfilintherestofthe contingencytable.Forexample,lo kingathesecondrowinthetable,weknow
that33 ad edtotheunknownnumberinthemid leis67,sothatunknownnumber is34.Continuinginthisway,wecanfilintheentiretable:
StudentsplaysportsdonotplaysportsTotalplayaninstrument273 360donotplayaninstrument353469Total6267129
From this,wecanse thathenumberofstudentswhobothdonotplaysportsanddo notplayaninstrumentis34.
QUESTION46 1/1POINTS
Theanswerchoicesbelowrepresentdifferenthypothesistests.Whichofthechoices areleft-tailedtests?Selectalcorectanswers.
•
H0:X=17.3,Ha:X≠17.3
•
•
H0:X≥19.7,Ha:X<19.7
•
•
H0:X≥11.2,Ha:X<11.2
•
•
H0:X=13.2,Ha:X≠13.2
•
•
H0:X=17.8,Ha:X≠17.8
•
AnswerExplanation
Corectanswer:
Remembertheformsofthehypothesistests.
Right-tailed:H0:X≤X0,Ha:X>X0.
Left-tailed:H0:X≥X0,Ha:X
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