MATH 225N Week 4 Statistics Quiz – Question and Answers
1/
1POI
NTS
Afit
nesscentercl
ai
mst hathemeanamountoftimethataper
sonspendsathegym
pervisi s33 mi
ti nutes.I
denti
fyt
henulhypot
hesi,H0,andt
s heal
ter
nati
ve
hy pot
hesis,Ha,i
ntermsofthepar erμ.
amet
Thati
scorect
!
H0:μ≠33;Ha:μ=33
H0:μ=33;Ha:μ≠33
H0:μ≥33;Ha:μ<33
H0:μ≤33;Ha:μ>33
AnswerExpl
anat
ion
Cor
rectanswer
:
H0:μ=33;Ha:μ≠33
Lethepar erμ beusedt
amet or epr
esenthemean.Thenulhypot hesi
sisalways
st
atedwithsomeform ofequalit
y:equal(=),gr
eat
erthanorequalto(≥),orlesst
han
orequalto(≤).Ther
efore,i
nt hi
scase,thenulhypothesisH0 i
sμ=33.The
al
ternat
i
vehypothesi
siscontradict
orytothenulhypothesi
s,soHa i
sμ≠33.
QUESTI
ON2
1/
1POINTS
Theanswerc hoi
cesbel
owr epr
esentdi
fer
enthypot
hesi
stest
s.Whi
choft
hechoi
ces
arer
ight
-tai
ledtest
s?Selectalcorr
ectanswers.
Thati
scorect
!
•
H0:X≥17.1,Ha:X<17.1
,MATH 225N Week 4 Statistics Quiz – Question and Answers
•
•
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
•
AnswerExpl
anat
ion
Cor
rectanswer
:
H0:X≤3.8,Ha:X>3.8
H0:X≤7.4,Ha:X>7.4
Remembert
hef
ormsoft
hehy
pot
hesi
stest
s.
• Ri
ght
-t
aied:H0:X≤X0,Ha:X>X0.
l
• Lef
t-
t ed:H0:X≥X0,Ha:X<X0.
ai
l
• Two-
t ed:H0:X=X0,Ha:X≠X0.
ai
l
,MATH 225N Week 4 Statistics Quiz – Question and Answers
Soi
nthi
scase,t
her
ight
-t
ail
edt
est
sar
e:
• H0:X≤7.4,Ha:X>7.4
• H0:X≤3.8,Ha:X>3.8
QUESTI
ON3
0/
1POINTS
Fi
ndtheType Ier
rorgi
vent
hathenulhypothesi
s,H0,i
s:abui
l
dinginspect
orc
lai
ms
t
hatnomorethan15% ofstruct
uresi
nthecountywer
ebuil
twi
thoutpermi
ts
.
That
'snotr
ight
.
Thebuil
dinginspect
ort
hinkst
hatnomoret
han15% oft
hest
ructur
esint
hecounty
werebuil
twit
houtpermi
tswhen,inf
act
,nomoret
han15% ofthestr
uct
uresr
ealywer
e
bui
l
twithoutpermit
s.
Thebuil
dinginspect
ort
hinkst
hatmorethan15% ofthestr
ucturesinthecountywere
bui
ltwi
thoutpermit
swhen,inf
act,mor
et han15% ofthest
ructuresreal
ywer ebui
lt
wit
houtpermits
.
Thebui
ldi
nginspect
ort
hinkst
hatmorethan15% ofthestruct
uresi
nthecountywer
e
bui
l
twit
houtpermit
swhen,inf
act,atmost15% oft
hestructur
eswerebui
ltwit
hout
per
mit
s.
Thebuil
dingi
nspectort
hinkst
hatnomoret
han15% oft
hestr
uct
uresint
hecount
y
werebuil
twit
houtpermi
tswhen,inf
act
,moret
han15% oft
hestr
uctur
eswer
ebuil
t
wit
houtpermi
ts.
AnswerExpl
anat
ion
Cor
rectanswer
:
Thebui
ldi
ngi
nspect
ort
hinkst
hatnomor
ethan15% oft
hest
ruct
uresi
nthecount
y
werebuil
twithoutper
mit
swhen,inf
act
,morethan15% oft hestruct
ureswerebuil
t
wi
thoutpermits.
AType Ier r
oristhedeci
si
onnotorej
ecthenulhypothesi
swhen,i nfact
,iti
sfal
se.I
n
t
hiscase,theType Ierr
oriswhent
hebui
ldi
nginspect
orthi
nksthatnomor e
,MATH 225N Week 4 Statistics Quiz – Question and Answers
han15% oft
t hest
ruct
ureswer
ebui
l
twi
t
houtper
mit
swhen,i
nfact
,mor
e
han15% oft
t hest
ruct
ureswer
ebui
l
twi
t
houtper
mit
s.
Youranswer
:
Thebui
ldi
ngi
nspect
ort
hinkst
hatmor
ethan15% oft
hest
ruct
uresi
nthecount
ywer
e
bui
ltwithoutper mitswhen,i nf act,atmost15% oft
hest
ruct
ureswer
ebui
l
twi
t
hout
permits.
Content attribution- Opens a dialog
QUESTI
ON4
1/
1POINTS
Sup
poseachefc laimst
hathermeatbalweighti
slessthan4 ounces,onaverage.
Sever
alofhercust omer
sdonotbeli
eveher,sothec hefdec
idest
odoahypot hesist
est
,
ata10% s igni
ficancelev
el,t
oper
suadethem.Sheco oks14 meatbals.Themean
wei
ghtoft
hesampl
emeat
bal
sis3.7 ounces.Thec
hefknowsf
rom exper
iencet
hat
the
st
andar
ddevi
ati
onf
orhermeat
balwei s0.5 ounces
ghti .
• H0:μ≥4;Ha:μ<4
• α=0.1 (
signi
ficancel
evel
)
Whati
sthet
estst
ati
st
i z-
c( scor
e)oft
hisone-
meanhypot
hesi
stest
,roundedt
otwo
dec
imalpl
aces
?
Thati
scorect
!
$$Test statistic = −2.24
AnswerExpl
anat
ion
Cor
rectanswer s:
• $\text{Test statistic = }-2.24$Test statistic = −2.24
Thehypot
heseswerechosen,andt
hesi
gni
ficancel
evelwasdec
idedon,sot
henext
st
epinhypot
hesi
stest
i
ngi st
ocomputet
heteststat
i
sti
c.I
nthi
sscenar
io,t
hesampl
e
meanwei ,x¯=3.7.Thesampl
ght et s14 meat
hechefusesi s,son=14.She
bal
knowst
hest
andar
ddev
iat
i
onoft
hemeat s,σ=0.5.Last
bal l
y,t
hechefi
scompar
ing
t
hepopul
ati ghto4 ounces
onmeanwei .So,t
hisv
alue(
foundi
nthenulandal
t
ernat
i
ve
1/
1POI
NTS
Afit
nesscentercl
ai
mst hathemeanamountoftimethataper
sonspendsathegym
pervisi s33 mi
ti nutes.I
denti
fyt
henulhypot
hesi,H0,andt
s heal
ter
nati
ve
hy pot
hesis,Ha,i
ntermsofthepar erμ.
amet
Thati
scorect
!
H0:μ≠33;Ha:μ=33
H0:μ=33;Ha:μ≠33
H0:μ≥33;Ha:μ<33
H0:μ≤33;Ha:μ>33
AnswerExpl
anat
ion
Cor
rectanswer
:
H0:μ=33;Ha:μ≠33
Lethepar erμ beusedt
amet or epr
esenthemean.Thenulhypot hesi
sisalways
st
atedwithsomeform ofequalit
y:equal(=),gr
eat
erthanorequalto(≥),orlesst
han
orequalto(≤).Ther
efore,i
nt hi
scase,thenulhypothesisH0 i
sμ=33.The
al
ternat
i
vehypothesi
siscontradict
orytothenulhypothesi
s,soHa i
sμ≠33.
QUESTI
ON2
1/
1POINTS
Theanswerc hoi
cesbel
owr epr
esentdi
fer
enthypot
hesi
stest
s.Whi
choft
hechoi
ces
arer
ight
-tai
ledtest
s?Selectalcorr
ectanswers.
Thati
scorect
!
•
H0:X≥17.1,Ha:X<17.1
,MATH 225N Week 4 Statistics Quiz – Question and Answers
•
•
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
•
AnswerExpl
anat
ion
Cor
rectanswer
:
H0:X≤3.8,Ha:X>3.8
H0:X≤7.4,Ha:X>7.4
Remembert
hef
ormsoft
hehy
pot
hesi
stest
s.
• Ri
ght
-t
aied:H0:X≤X0,Ha:X>X0.
l
• Lef
t-
t ed:H0:X≥X0,Ha:X<X0.
ai
l
• Two-
t ed:H0:X=X0,Ha:X≠X0.
ai
l
,MATH 225N Week 4 Statistics Quiz – Question and Answers
Soi
nthi
scase,t
her
ight
-t
ail
edt
est
sar
e:
• H0:X≤7.4,Ha:X>7.4
• H0:X≤3.8,Ha:X>3.8
QUESTI
ON3
0/
1POINTS
Fi
ndtheType Ier
rorgi
vent
hathenulhypothesi
s,H0,i
s:abui
l
dinginspect
orc
lai
ms
t
hatnomorethan15% ofstruct
uresi
nthecountywer
ebuil
twi
thoutpermi
ts
.
That
'snotr
ight
.
Thebuil
dinginspect
ort
hinkst
hatnomoret
han15% oft
hest
ructur
esint
hecounty
werebuil
twit
houtpermi
tswhen,inf
act
,nomoret
han15% ofthestr
uct
uresr
ealywer
e
bui
l
twithoutpermit
s.
Thebuil
dinginspect
ort
hinkst
hatmorethan15% ofthestr
ucturesinthecountywere
bui
ltwi
thoutpermit
swhen,inf
act,mor
et han15% ofthest
ructuresreal
ywer ebui
lt
wit
houtpermits
.
Thebui
ldi
nginspect
ort
hinkst
hatmorethan15% ofthestruct
uresi
nthecountywer
e
bui
l
twit
houtpermit
swhen,inf
act,atmost15% oft
hestructur
eswerebui
ltwit
hout
per
mit
s.
Thebuil
dingi
nspectort
hinkst
hatnomoret
han15% oft
hestr
uct
uresint
hecount
y
werebuil
twit
houtpermi
tswhen,inf
act
,moret
han15% oft
hestr
uctur
eswer
ebuil
t
wit
houtpermi
ts.
AnswerExpl
anat
ion
Cor
rectanswer
:
Thebui
ldi
ngi
nspect
ort
hinkst
hatnomor
ethan15% oft
hest
ruct
uresi
nthecount
y
werebuil
twithoutper
mit
swhen,inf
act
,morethan15% oft hestruct
ureswerebuil
t
wi
thoutpermits.
AType Ier r
oristhedeci
si
onnotorej
ecthenulhypothesi
swhen,i nfact
,iti
sfal
se.I
n
t
hiscase,theType Ierr
oriswhent
hebui
ldi
nginspect
orthi
nksthatnomor e
,MATH 225N Week 4 Statistics Quiz – Question and Answers
han15% oft
t hest
ruct
ureswer
ebui
l
twi
t
houtper
mit
swhen,i
nfact
,mor
e
han15% oft
t hest
ruct
ureswer
ebui
l
twi
t
houtper
mit
s.
Youranswer
:
Thebui
ldi
ngi
nspect
ort
hinkst
hatmor
ethan15% oft
hest
ruct
uresi
nthecount
ywer
e
bui
ltwithoutper mitswhen,i nf act,atmost15% oft
hest
ruct
ureswer
ebui
l
twi
t
hout
permits.
Content attribution- Opens a dialog
QUESTI
ON4
1/
1POINTS
Sup
poseachefc laimst
hathermeatbalweighti
slessthan4 ounces,onaverage.
Sever
alofhercust omer
sdonotbeli
eveher,sothec hefdec
idest
odoahypot hesist
est
,
ata10% s igni
ficancelev
el,t
oper
suadethem.Sheco oks14 meatbals.Themean
wei
ghtoft
hesampl
emeat
bal
sis3.7 ounces.Thec
hefknowsf
rom exper
iencet
hat
the
st
andar
ddevi
ati
onf
orhermeat
balwei s0.5 ounces
ghti .
• H0:μ≥4;Ha:μ<4
• α=0.1 (
signi
ficancel
evel
)
Whati
sthet
estst
ati
st
i z-
c( scor
e)oft
hisone-
meanhypot
hesi
stest
,roundedt
otwo
dec
imalpl
aces
?
Thati
scorect
!
$$Test statistic = −2.24
AnswerExpl
anat
ion
Cor
rectanswer s:
• $\text{Test statistic = }-2.24$Test statistic = −2.24
Thehypot
heseswerechosen,andt
hesi
gni
ficancel
evelwasdec
idedon,sot
henext
st
epinhypot
hesi
stest
i
ngi st
ocomputet
heteststat
i
sti
c.I
nthi
sscenar
io,t
hesampl
e
meanwei ,x¯=3.7.Thesampl
ght et s14 meat
hechefusesi s,son=14.She
bal
knowst
hest
andar
ddev
iat
i
onoft
hemeat s,σ=0.5.Last
bal l
y,t
hechefi
scompar
ing
t
hepopul
ati ghto4 ounces
onmeanwei .So,t
hisv
alue(
foundi
nthenulandal
t
ernat
i
ve
