




















































































Study with the several resources on Docsity
Earn points by helping other students or get them with a premium plan
Prepare for your exams
Study with the several resources on Docsity
Earn points to download
Earn points by helping other students or get them with a premium plan
MATH 225N MATH Statistic Final Correct Approved
Typology: Exams
1 / 92
This page cannot be seen from the preview
Don't miss anything!





















































































Afitnesscenterclaimstha t hemeanamountoft
imethatapersonspendsa t hegym
dthealternative
H 0 :μ≠ 33 ;Ha:μ
H 0 :μ= 33 ;Ha:μ
H 0 :μ≥ 33 ;Ha:μ
H 0 :μ≤ 33 ;Ha:μ> 33
Co r
ectanswer:
beusedtorepresen t hemean.Thenu l hypothesisisa
lways statedwithsomeform
,orlessthan
alternativehypothesisiscontradictorytothenu
Theanswerchoicesbelowrepresentdiffere
nthypothesistests.Whichofthechoices
areright-tailedtests?
Thatisco r ect!
Thatisco r ect!
Selecta l co r ectanswers.
withoutpermits.
Sointhiscase,theright-tailedtestsare:
FindtheType
ofstructuresinthecountywerebuiltwithoutpermi
ts.
Thebuildinginspectorthinksthatnomorethan 15 %
ofthestructuresinthecounty
werebuiltwithoutpermitswhen,infact,nomoretha
n 15 % ofthestructuresrea l ywere
builtwithoutpermits.
Thebuildinginspectorthinksthatmorethan 1
5 % ofthestructuresinthecountywere
builtwithoutpermitswhen,infact,moretha
n 15 % ofthestructuresrea l ywerebuilt
withoutpermits.
Thebuildinginspectorthinksthatmorethan 1
5 % ofthestructuresinthecountywere
builtwithoutpermitswhen,infact,atmost 15
% ofthestructureswerebuiltwithout
permits.
Thebuildinginspectorthinksthatnomoret
han 15 % ofthestructuresinthecounty
werebuiltwithoutpermitswhen,infact,m
orethan 15 % ofthestructureswerebuilt
withoutpermits.
Co r
ectanswer:
AType
I e r oristhedecisionno t orejec t henu l hypothesisw
hen,infact,itisfalse.In thiscase,theType
I e r oriswhenthebuildinginspectorthinksthatnom
That'snotright.
ore
Lastly,thechefiscomparing
ounces.So,thisvalue(foundinthenu l andalterna
tive
aluesintotheformulatocomputethe
teststatistic:
meanhypothesistest,withateststatistic
(Donotroundyouranswer;computeyouransw
erusingavaluefrom the tablebelow.)
valueistheprobabilityofanobservedvalue
hypothesisistrue,becausethishypothesi
stestisright-
tailed.Thisprobabilityisequalto
theareaundertheStandardNormalcurvetot
Thatisco r ect!
Thatisco r ect!
Donotrejec t
henu l hypothesisbecausethep-
value 0. 0401 isgreaterthanthe
significancelevelα=0. 04.
Rejec t
henu l hypothesisbecausethep-value 0. 0401
isgreaterthanthesignificance levelα=0.04.
Rejec t
henu l hypothesisbecau
sethevalueofz isnegative.
Rejec t
henu l hypothesisbecau
se|−1.75|> 0. 04.
Donotrejec t
henu l hypothesisbecause|−1. 75 |> 0. 04.
Co r
ectanswer:
Inmakingthedecisiontorejectornotreject
resultsofthesampledataaresignificant.Th
isaninco r ectbeliefandtha t healternativ
pledataarenotsignificant,so
thereisnotsufficientevidencetoconcludeth
nis tonotrejec t henu l hypothesis.
Arecentstudysu g
ofseniorcitizenstakeatleastoneprescrip
tion
medication.Ameliaisanurseatalargehospi
talwhowouldliketoknowwhetherthe
percentageisthesameforseniorcitizenpat
ientswhogotoherhospital.Sherandomly
Thatisco r ect!
{H 0 :p=0.81Ha:p>0.
{H 0 :p≠0.81Ha:p=0.
{H 0 :p=0.81Ha:p<0.
{H 0 :p=0.81Ha:p≠0.
Co r
ectanswer:
Firstverifywhethera l oftheconditionshaveb e
proportionfortheseniorcitizenpatientstreated
atAmelia'shospitalwhotakeatleast
oneprescriptionmedication.
sforeachtrial,theproportionfo l owsa
binomialmodel.
l ectedrandomly.
,andtheexpectednumberof
SinceAmeliaistestingwhethertheproport
Thenu l andalternativehypothesesareshow
nbelow.
Aresearcherclaimstha t
heproportionofcar
swithmanualtransmissionisless
t
hisclaim,asurveychecked
Thefo l owingisthesetupforthehypothesistest:
Thefo l owingtablecanbeutilizedwhichprovidesar easundertheStandardNormal Curve: AnswerExplanation
r ectanswers:
Herearethestepsn e dedtocalculatethep- valueforahypothesistestforaproportion: 1 .Determineifthehypothesistestislef t ailed, righ t ailed,ortwotailed. 2 .Computethevalueoftheteststatistic. 3 .Ifthehypothesistestislef t ailed,the p-valuewi l betheareaunderthestandard normalcurvetotheleftoftheteststatistic z 0 Ifthetestisrigh t ailed,thep- valuewi l betheareaunderthestandardnormal curvetotherightoftheteststatistic z 0 Ifthetestistwotailed,thep- valuewi l betheareatotheleftof−| z 0 |plusthe areatotherightof| z 0 | underthestandardnormalcurve Forthisexample,thetestisatwotailedte standtheteststatistic,roundingtotwo
−−−−−−−−− −−−√≈− 1. 54.
z 0.00 0.01 0.02 0.03 0.04 0.05 0.06 0.07 0.08 0.
Thatisco r ect!
Thusthep- valueistheareaundertheStandardNormalcurveto theleftofaz-scoreof
ON 10 1 / 1 POIN TS
Aneconomistclaimstha t heproportionofpeoplewho plantopurchaseafu l yelectric
Totes t
peopleareaskediftheyplantopurchasea fu l yelectricvehicleastheirnextcar
t heydo plantopurchaseanelectricvehicle. Thefo l owingisthesetupforthishypothesistest:
5 Ha:p>0. 5
Inthisexample,thep-
z 0.00 0.01 0.02 0.03 0.04 0.05 0.06 0.07 0.08 0.
Thedecisionistorejec t heNu l Hypothesis.
Theconclusionistha t hereisenoughevidenc
etosu p or t heclaim.
Thatisco r ect!
Thedecisionistorejec t
heNu l Hypothesis.
Theconclusionistha t
hereisenoughevidencetosu p
or t
heclaim.
Thedecisionistofailtorejec t
heNu l Hypothesis.
Theconclusionistha t
hereisnotenoughevidenceto
su p
or t
heclaim.
AnswerExplanation
Co r
ectanswer:
Tocometoaconclusionandinterpre t heres
ultsforahypothesistestforproportion
usingtheP-ValueA p
roach,thefirststepistocomparethep-
valuefrom thesample
datawiththelevelofsignificance.
Thedecisioncriteriaisthenasfo l ows:
valueislessthanorequaltothegivensignificance
level,thenthenu l
hypothesisshouldberejected.
Whenwehavemadeadecisionabou t henu l hypothesis
,itisimportan t owritea
thoughtfulconclusionabou t hehypothesesinterms
ofthegivenproblem'sscenario.
Assumingtheclaim
isthenu l hypothesis,theconclusionisthenoneoft
hefo l owing:
esis,thentheconclusionistha t hereis
enoughevidencetorejec t heclaim.
hypothesis,thentheconclusionistha
t
thereisnotenoughevidencetorejec t h
eclaim.
Assumingtheclaim
isthealternativehypothesis,theconclusi
onisthenoneofthe fo l owing: