Ch.2 DescriptiveStatistics
2.1 FrequencyDistributionsandTheirGraphs
1 InterpretaFrequencyDistribution
MULTIPLECHOICE.Choosetheonealternativethatbestcompletesthestatementoranswersthequestion.
Usethegivenfrequencydistributiontofindthe
(a)classwidth.
(b)classmidpointsofthefirstclass.
(c)classboundariesofthefirstclass.
1) Height(ininches)
Class Frequency,f
50–52 5
53–55 8
56–58 12
59–61 13
62–64 11
A) (a)3
(b)51
(c)49.5–52.5
B) (a)2
(b)51.5
(c)49.5–52.5
C) (a)3
(b)51
(c)50–52
D) (a)2
(b)51.5
(c)50–52
2) PhoneCalls(perday)
Class Frequency,f
8–11 18
12–15 23
16–19 38
20–23 47
24–27 32
A) (a)4
(b)9.5
(c)7.5–11.5
B) (a)3
(b)10.5
(c)8–11
C) (a)4
(b)10.5
(c)8–11
D) (a)3
(b)9.5
(c)7.5–11.5
3) Weight(inpounds)
Class Frequency,f
135–139 6
140–144 4
145–149 11
150–154 15
155–159 8
A) (a)5
(b)137
(c)134.5–139.5
B) (a)5
(b)137
(c)135–139
C) (a)4
(b)137.5
(c)134.5–139.5
D) (a)4
(b)137.5
(c)135–139
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4) Miles(perday)
Class Frequency,f
1–29
3–422
5–628
7–815
9–10 4
A) (a)2
(b)1.5
(c)0.5–2.5
B) (a)1
(b)1.5
(c)0.5–2.5
C) (a)2
(b)1
(c)1–2
D) (a)1
(b)1
(c)1–2
SHORTANSWER.Writethewordorphrasethatbestcompleteseachstatementoranswersthequestion.
Usethemaximumandminimumdataentriesandthenumberofclassestofindtheclasswidth,thelowerclasslimits,
andtheupperclasslimits.
5) min=1,max=30,6classes
6) min=80,max=265,6classes
2 InterpretFrequencyDistributionGraphs
MULTIPLECHOICE.Choosetheonealternativethatbestcompletesthestatementoranswersthequestion.
Provideanappropriateresponse.
1) Usetheogivebelowtoapproximatethenumberinthesample.
A) 80 B) 100 C) 341 D) 28
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2) Usetheogivebelowtoapproximatethecumulativefrequencyfor24hours.
A) 63 B) 17 C) 27 D) 75
SHORTANSWER.Writethewordorphrasethatbestcompleteseachstatementoranswersthequestion.
Usetherelativefrequencyhistogramto
a)identifytheclasswiththegreatest,andtheclasswiththeleast,relativefrequency.
b)approximatethegreatestandleastrelativefrequencies.
c)approximatetherelativefrequencyofthefifthclass.
3)
Usethegivenfrequencydistributiontoconstructafrequencyhistogram,arelativefrequencyhistogramandafrequency
polygon.
4) Height(ininches)
Class Frequency,f
50–52 5
53–55 8
56–58 12
59–61 13
62–64 11
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5) Weight(inpounds)
Class Frequency,f
135–139 6
140–144 4
145–149 11
150–154 15
155–159 8
Usethegivenfrequencydistributiontoconstructacumulativefrequencydistributionandanogive.
6) PhoneCalls(perday)
Class Frequency,f
8–11 18
12–15 23
16–19 38
20–23 47
24–27 32
7) Height(ininches)
Class Frequency,f
50–52 5
53–55 8
56–58 12
59–61 13
62–64 11
8) Weight(inpounds)
Class Frequency,f
135–139 6
140–144 4
145–149 11
150–154 15
155–159 8
9) Miles(perday)
Class Frequency,f
1–29
3–422
5–628
7–815
9–10 4
3 ConstructaFrequencyDistributionfromDataSet
MULTIPLECHOICE.Choosetheonealternativethatbestcompletesthestatementoranswersthequestion.
Provideanappropriateresponse.
1) AcityinthePacificNorthwestrecordeditshighesttemperatureat91 degreesFahrenheitanditslowest
temperatureat12degreesFahrenheitforaparticularyear.Usethisinformationtofindtheupperandlower
limitsofthefirstclassifyouwishtoconstructafrequencydistributionwith10classes.
A) 12–19 B) 12–20 C) 7–17 D) 12–18
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2) Asampleofcandieshaveweightsthatvaryfrom2.35gramsto4.75grams.Usethisinformationtofindthe
upperandlowerlimitsofthefirstclassifyouwishtoconstructafrequencydistributionwith12classes.
A) 2.35–2.55 B) 2.35–2.54 C) 2.35–2.65 D) 2.35–2.75
SHORTANSWER.Writethewordorphrasethatbestcompleteseachstatementoranswersthequestion.
Thegradepointaveragesfor40studentsarelistedbelow.
2.0 3.2 1.8 2.9 0.9 4.0 3.3 2.9 3.6 0.8
3.1 2.4 2.4 2.3 1.6 1.6 4.0 3.1 3.2 1.8
2.2 2.2 1.7 0.5 3.6 3.4 1.9 2.0 3.0 1.1
3.0 4.0 4.0 2.1 1.9 1.1 0.5 3.2 3.0 2.2
3) Constructafrequencydistribution,arelativefrequencydistribution,andacumulativefrequencydistribution
usingeightclasses.Includethemidpointsoftheclasses.
4) Constructafrequencyhistogram,arelativefrequencyhistogramandafrequencypolygonusingeightclasses.
5) Constructanogiveusingeightclasses.
Theheights(ininches)of30adultmalesarelistedbelow.
70 72 71 70 69 73 69 68 70 71
67 71 70 74 69 68 71 71 71 72
69 71 68 67 73 74 70 71 69 68
6) Constructafrequencydistribution,arelativefrequencydistribution,andacumulativefrequencydistribution
usingfiveclasses.
7) Constructafrequencyhistogramusingfiveclasses.
8) Constructarelativefrequencyhistogramusingfiveclasses.
9) Constructafrequencypolygonusingfiveclasses.
10) Constructaogiveusingfiveclasses.
TheHighwayPatrol,usingradar,checkedthespeeds(inmph)of30passingmotoristsatacheckpoint.Theresultsare
listedbelow.
44 38 41 50 36 36 43 42 49 48
35 40 37 41 43 50 45 45 39 38
50 41 47 36 35 40 42 43 48 33
11) Constructafrequencydistribution,arelativefrequencydistribution,andacumulativefrequencydistribution
usingsixclasses.
12) Constructafrequencyhistogram,arelativefrequencyhistogramandafrequencypolygonusingsixclasses.
13) Constructanogiveusingsixclasses.
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Provideanappropriateresponse.
14) ListedbelowaretheACTscoresof40randomlyselectedstudentsatamajoruniversity.
18 22 13 15 24 24 20 19 19 12
16 25 14 19 21 23 25 18 18 13
26 26 25 25 19 17 18 15 13 21
19 19 14 24 20 21 23 22 19 17
a)Constructarelativefrequencyhistogramofthedata,usingeightclasses.
b)Iftheuniversitywantstoacceptthetop90%oftheapplicants,whatshouldtheminimumscorebe?
c)Iftheuniversitysetstheminimumscoreat17,whatpercentoftheapplicantswillbeaccepted?
4Concepts
SHORTANSWER.Writethewordorphrasethatbestcompleteseachstatementoranswersthequestion.
Provideanappropriateresponse.
1) Explainthedifferencebetweenclasslimitsandclassboundaries.
2.2 MoreGraphsandDisplays
1 InterpretDataSets
MULTIPLECHOICE.Choosetheonealternativethatbestcompletesthestatementoranswersthequestion.
Matchthedescriptionofthesamplewiththecorrectplot.
1) Time(inminutes)ittakesasampleofemployeestodrivetowork
A) B)
C) Key:09=0.9
0
1
2
3
4
9
49
3678
01568
0
D) Key:72=72
6
7
8
9
89
0233678
2456778
0115
SHORTANSWER.Writethewordorphrasethatbestcompleteseachstatementoranswersthequestion.
Provideanappropriateresponse.
2) ThenumbersofhomerunsthatSammySosahitinthefirst15yearsofhismajorleaguebaseballcareerare
listedbelow.Makeastem–and–leafplotforthisdata.Whatcanyouconcludeaboutthedata?
415 10 833 25 36 40 36 66 63 50 64 49 40
3) ThenumbersofhomerunsthatBarryBondshitinthefirst18yearsofhismajorleaguebaseballcareerare
listedbelow.Makeastem–and–leafplotforthisdata.Whatcanyouconcludeaboutthedata?
16 25 24 19 33 25 34 46 37
33 42 40 37 34 49 73 46 45
Page15
MULTIPLECHOICE.Choosetheonealternativethatbestcompletesthestatementoranswersthequestion.
4) Forthestem–and–leafplotbelow,whatisthemaximumandwhatistheminimumentry?
Key:11 9=11.9
11
12
13
14
15
16
17
69
466789
0112366788
34668999
011237789
22578899
78
A) max:17.8;min:11.6 B) max:178;min:116
C) max:17.7;min:11.6 D) max:17.8;min:11.9
5) Forthedotplotbelow,whatisthemaximumandwhatistheminimumentry?
A) max:17;min:12 B) max:54;min:15 C) max:54;min:12 D) max:14;min:12
SHORTANSWER.Writethewordorphrasethatbestcompleteseachstatementoranswersthequestion.
6) Theheights(ininches)of30adultmalesarelistedbelow.Constructastem–and–leafchartforthedata.
Whatcanyouconcludeaboutthedata?
70 72 71 70 69 73 69 68 70 71
67 71 70 74 69 68 71 71 71 72
69 71 68 67 73 74 70 71 69 68
7) TheHighwayPatrol,usingradar,checkedthespeeds(inmph)of30passingmotoristsatacheckpoint.The
resultsarelistedbelow.Constructastem–and–leafplotforthedata,listingeachstemtwice.Whatcanyou
concludeaboutthedata?
44 38 41 50 36 36 43 42 49 48
35 40 37 41 43 50 45 45 39 38
50 41 47 36 35 40 42 43 48 33
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2 GraphDataSets
MULTIPLECHOICE.Choosetheonealternativethatbestcompletesthestatementoranswersthequestion.
Provideanappropriateresponse.
1) Displaythedatabelowinastem–and–leafplot.
A)
6
7
8
0455677799
0224589
1
B)
5
6
7
8
9
456688899
0114589
1
C)
6
7
8
0466788899
0224579
1
D)
5
6
7
8
0
0
7
1
SHORTANSWER.Writethewordorphrasethatbestcompleteseachstatementoranswersthequestion.
2) TheHighwayPatrol,usingradar,checkedthespeeds(inmph)of30passingmotoristsatacheckpoint.The
resultsarelistedbelow.Constructadotplotforthedata.
44 38 41 50 36 36 43 42 49 48
35 40 37 41 43 50 45 45 39 38
50 41 47 36 35 40 42 43 48 33
3) Theheights(ininches)of30adultmalesarelistedbelow.Constructadotplotforthedata.
70 72 71 70 69 73 69 68 70 71
67 71 70 74 69 68 71 71 71 72
69 71 68 67 73 74 70 71 69 68
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4) Astudywasconductedtodeterminehowpeoplegetjobs.Fourhundredsubjectswererandomlyselectedand
theresultsarelistedbelow.
JobSourcesof
SurveyRespondents Frequency
Newspaperwantads 69
Onlineservices 124
Executivesearchfirms 72
Mailings 32
Networking 103
Constructapiechartofthedata.
5) Astudywasconductedtodeterminehowpeoplegetjobs.Fourhundredsubjectswererandomlyselectedand
theresultsarelistedbelow.
JobSourcesof
SurveyRespondents Frequency
Newspaperwantads 72
Onlineservices 124
Executivesearchfirms 69
Mailings 32
Networking 103
ConstructaParetochartofthedata.
6) Theheights(ininches)of30adultmalesarelistedbelow.ConstructaParetochartforthedata.
70 72 71 70 69 73 69 68 70 71
67 71 70 74 69 68 71 71 71 72
69 71 68 67 73 74 70 71 69 68
7) Useascatterplottodisplaythedatabelow.Allmeasurementsareinmilligramspercigarette.
Brand Tar Nicotine
Benson&Hedges 16 1.2
LuckyStrike 13 1.1
Marlboro 16 1.2
Viceroy 18 1.4
True 6 0.6
8) ThenumbersofhomerunsthatBarryBondshitinthefirst10yearsofhismajorleaguebaseballcareerare
listedbelow.Useascatterplottodisplaythedata.Istherearelationshipbetweenthehomerunsandthe
battingaverages?
HomeRuns
BattingAverage
16 25 24 19 33 25 34 46 37 33
.223 .261 .283 .248 .301 .292 .311 .336 .312 .294
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9) Thedatabelowrepresentthenumbersofabsencesandthefinalgradesof15randomlyselectedstudentsfroma
statisticsclass.Useascatterplottodisplaythedata.Istherearelationshipbetweenthestudentsʹabsencesand
theirfinalgrades?
Student NumberofAbsences FinalGradeasaPercent
15 79
26 78
32 86
412 56
59 75
65 90
78 78
815 48
90 92
10 1 78
11 9 81
12 3 86
13 10 75
14 3 89
15 11 65
10) Thedatabelowrepresenttheinfantmortalityratesandthelifeexpectanciesforsevenselectedcountriesin
Africa.Useascatterplottodisplaythedata.
InfantMortality 63 199 71 61 67 35 194
LifeExpectancy 45 31 51 47 39 70 37
11) ThedatabelowrepresentthesmokingprevalenceamongU.S.adultsovera35 –yearperiod.Useatimeseries
charttodisplaythedata.Describeanytrendsshown.
Year 1965 1985 1990 1995 2000
PercentofSmokers 42 30 25 25 23
12) Asafetyengineerwishestousethefollowingdatatoshowthenumberofdeathsfromthecollisionof
passengercarswithtrucksonaparticularhighway.Useatimeseriescharttodisplaythedata.Describeany
trendsshown.
Year NumberofDeaths
1930 12
1940 17
1950 22
1960 21
1970 16
1980 13
1990 11
2000 12
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13) WomenwereallowedtoentertheBostonMarathonforthefirsttimein1972.Listedbelowarethewinning
womenʹstimes(inminutes)forthefirst10years.Useatimeseriescharttodisplaythedata.
Year
Time
1972 1973 1974 1975 1976 1977 1978 1979 1980 1981
190 186 167 162 167 168 165 155 154 147
14) ThefivelongestwinningstreaksforNCAAMenʹsDivisionIBasketballarelistedbelow.ConstructaPareto
chartforthedata.
University NumberofGames
Indiana 57
SanFrancisco 51
UCLA 76
Marquette 56
Kentucky 54
15) Thelengths,inkilometers,oftheworldʹslargestsubwaysystemsarelistedbelow.ConstructaParetochartfor
thedata.
City Length
Moscow 340
Paris 211
London 415
Tokyo 281
NewYorkCity 371
16) Thenumberofbedsinasampleof24hospitalsarelistedbelow.Constructastem –and–leafplotforthedata.
149 167 162 127 130 180 160 167
221 145 137 194 207 150 254 262
244 287 137 204 166 174 180 151
17) Thenumberofminutesthatadentistkept20patientswaitingbeyondtheirappointmenttimesarelistedbelow.
Constructastem–and–leafplotforthedata.
12.9 12.1 9.6 9.8 11.5 13.0 10.5 10.3 15.7 11.3
10.7 10.0 13.0 9.7 11.4 12.8 11.9 9.3 9.6 10.1
18) Astudywasconductedtodeterminehowcertainfamiliespayontheircreditcardbalances.Twohundred
familieswithahouseholdannualincomebetween$25,000and$49,999wererandomlyselectedandtheresults
arelistedbelow.Constructapiechartofthedata.
Paymentschedule Frequency
Almostalwayspayoffbalance 97
Sometimespayoffbalance 41
Hardlyeverpayoffbalance 62
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19) Ofthe55tornadofatalitiesinarecentyear,thelocationsofthevictimsarelistedbelow.Constructapiechart
ofthedata.
Location Fatalities
Mobilehome 37
Permanenthome 10
Vehicle 4
Business 2
Unknown 2
20) Thedatabelowrepresentthealcohol–relateddrivingfatalities,inthousands,intheUnitedStatesovera
20–yearperiod.Useatimeseriescharttodisplaythedata.Describeanytrendsshown.
Year 1983 1985 1987 1989 1991 1993 1995 1997 19992001
Fatalities 25 23 24 22 20 18 18 17 1717
21) Thegraphbelowshowsthenumberofcaraccidentsoccurringinonecityineachoftheyears1through6.The
numberofaccidentsdroppedinyear3afteranewspeedlimitwasimposed.Doesthegraphdistortthedata?
Howwouldyouredesignthegraphtobelessmisleading?
Page21
2.3 MeasuresofCentralTendency
1 InterprettheGraphofaDistribution
MULTIPLECHOICE.Choosetheonealternativethatbestcompletesthestatementoranswersthequestion.
Provideanappropriateresponse.
1) Determinewhethertheapproximateshapeofthedistributioninthehistogramissymmetric,uniform,skewed
left,skewedright,ornoneofthese.
A) skewedright B) skewedleft C) symmetric D) uniform
2) Determinewhethertheapproximateshapeofthedistributioninthehistogramissymmetric,uniform,skewed
left,skewedright,ornoneofthese.
A) skewedleft B) skewedright C) symmetric D) uniform
Page22
3) Findthemean,median,andmodeofthedata.
A) x=70;median=69;mode=67 B) x≈70.1;median=69;mode=68
C) x≈70.3;median=69;mode=68 D) x=70;median=67;mode=69
Forthegivendata,constructafrequencydistributionandfrequencyhistogramofthedatausingfiveclasses.Describe
theshapeofthehistogramassymmetric,uniform,skewedleft,orskewedright.
4) Dataset:CaliforniaPickThreeLottery
3676061784
1575915399
2230884024
A) uniform B) symmetric C) skewedleft D) skewedright
5) Dataset:CaliforniaPickThreeLottery
8676091784
1575975399
8839889027
A) skewedleft B) symmetric C) uniform D) skewedright
6) Dataset:agesof20carsrandomlyselectedinastudentparkinglot
12 64911 17898
913 515 768821
A) symmetric B) uniform C) skewedleft D) skewedright
7) Dataset:systolicbloodpressuresof20randomlyselectedpatientsatabloodbank
135 120 115 132 136 124 119 145 98 110
125 120 115 130 140 105 116 121 125 108
A) symmetric B) uniform C) skewedleft D) skewedright
Page23
Provideanappropriateresponse.
8) Usethehistogrambelowtoapproximatethemodeheartrateofadultsinthegym.
A) 70 B) 42 C) 55 D) 2
9) Usethehistogrambelowtoapproximatethemedianheartrateofadultsinthegym.
A) 70 B) 65 C) 75 D) 42
10) Usethehistogrambelowtoapproximatethemeanheartrateofadultsinthegym.
A) 70.8 B) 1425.7 C) 70 D) 31.6
Page24
2 FindtheMean,Median,andMode
SHORTANSWER.Writethewordorphrasethatbestcompleteseachstatementoranswersthequestion.
Provideanappropriateresponse.
1) Findthemean,median,andmodeofthefollowingnumbers:
65 68 61 65 58 66 65 59 60 63
MULTIPLECHOICE.Choosetheonealternativethatbestcompletesthestatementoranswersthequestion.
2) Thetop14speeds,inmilesperhour,forPro–Stockdragracingoverthepasttwodecadesarelistedbelow.
Findthemeanspeed.
181.1 202.2 190.1 201.4 191.3 201.4 192.2
201.2 193.2 201.2 194.5 199.2 196.0 196.2
A) 195.8 B) 196.1 C) 201.2 D) 210.9
3) Thescoresofthetoptenfinishersinarecentgolftournamentarelistedbelow.Findthemeanscore.
71 67 67 72 76 72 73 68 72 72
A) 71 B) 67 C) 68 D) 72
SHORTANSWER.Writethewordorphrasethatbestcompleteseachstatementoranswersthequestion.
4) ThenumbersofrunsbattedinthatSammySosahitinthefirst15yearsofhismajorleaguebaseballcareerare
listedbelow.Findthemeanandmediannumberofrunsbattedin.Roundthemeantothenearestwhole
number.
13 70 33 25 93 70 119 100
119 158 141 138 160 108 103
5) ThenumbersofhomerunsthatBarryBondshitinthefirst18yearsofhismajorleaguebaseballcareerare
listedbelow.Findthemeanandmediannumberofhomeruns.Roundthemeantothenearestwholenumber.
Whichmeasureofcentraltendency–themeanorthemedian–bestrepresentsthedata?Explainyour
reasoning.
16 25 24 19 33 25 34 46 37
33 42 40 37 34 49 73 46 45
MULTIPLECHOICE.Choosetheonealternativethatbestcompletesthestatementoranswersthequestion.
6) Thetop14speeds,inmilesperhour,forPro–Stockdragracingoverthepasttwodecadesarelistedbelow.
Findthemedianspeed.
181.1 202.2 190.1 201.4 191.3 201.4 192.2
201.2 193.2 201.2 194.5 199.2 196.0 196.2
A) 196.1 B) 196.7 C) 195.8 D) 201.2
Page25
7) Thescoresofthetoptenfinishersinarecentgolftournamentarelistedbelow.Findthemedianscore.
67676871727272727376
A) 72 B) 67 C) 71 D) 73
8) Thetop14speeds,inmilesperhour,forPro–Stockdragracingoverthepasttwodecadesarelistedbelow.
Findthemodespeed.
181.1 202.2 190.1 201.4 191.3 201.4 192.2
201.2 193.2 201.2 194.5 199.2 196.0 196.2
A)
b
imodal:201.2,201.4 B) 201.4
C) 201.2 D) nomode
9) Thescoresofthetoptenfinishersinarecentgolftournamentarelistedbelow.Findthemodescore.
71 67 67 72 76 72 73 68 72 72
A) 72 B) 67 C) 76 D) 73
SHORTANSWER.Writethewordorphrasethatbestcompleteseachstatementoranswersthequestion.
10) TheamountsofmoneywonbythetoptenfinishersinarecentDaytona500arelistedbelow.Findthemean
andmedianwinnings.Roundtothenearestdollar.Whichmeasure–themeanorthemedian–bestrepresents
thedata?Explainyourreasoning.
$2,194,246 $464,084 $164,096 $199,209 $438,834
$613,659 $142,884 $240,731 $145,809 $290,596
3FindtheWeightedMean
MULTIPLECHOICE.Choosetheonealternativethatbestcompletesthestatementoranswersthequestion.
Provideanappropriateresponse.
1) Astudentreceivestestscoresof62,83,and91.Thestudentʹsfinalexamscoreis88andhomeworkscoreis76.
Eachtestisworth20%ofthefinalgrade,thefinalexamis25%ofthefinalgrade,andthehomeworkgradeis
15%ofthefinalgrade.Whatisthestudentʹsmeanscoreintheclass?
A) 80.6 B) 76.6 C) 90.6 D) 85.6
2) Gradepointsareassignedasfollows:A=4,B=3,C=2,D=1,andF=0.Gradesareweightedaccordingto
credithours.IfastudentreceivesanAinafour–creditclass,aDinatwo–creditclass,aBinathree–credit
classandaCinathree–creditclass,whatisthestudentʹsgradepointaverage?
A) 2.75 B) 1.75 C) 2.50 D) 3.00
Page26
4 FindtheMeanofFrequencyDistribution
MULTIPLECHOICE.Choosetheonealternativethatbestcompletesthestatementoranswersthequestion.
Approximatethemeanofthefrequencydistribution.
1)
Miles(perday) Frequency
1–215
3–428
5–611
7–814
9–10 9
A) 5 B) 4 C) 6 D) 15
2)
Phonecalls(perday) Frequency
8–11 37
12–15 49
16–19 17
20–23 46
24–27 39
A) 18 B) 17 C) 16 D) 19 E) 38
3)
Weight(inpounds) Frequency
135–139 7
140–144 12
145–149 10
150–154 11
155–159 20
A) 149 B) 147 C) 151 D) 12
5 Concepts
SHORTANSWER.Writethewordorphrasethatbestcompleteseachstatementoranswersthequestion.
Provideanappropriateresponse.
1) Whatisthedifferencebetweenusingμandxtorepresentamean?
2) Whydodataentriesneedtobeorderedbeforethemediancanbefound?
3) OnarecentStatisticstest,thescoreswere15,66,66,81,82,83,85,88,90,92,93,and95.Isthemeanagood
representationofthecenterofdata?Ifnot,why?
4) OnarecentStatisticstest,thescoreswere15,66,66,81,82,83,85,88,90,92,93,and95.Isthemodeagood
representationofthecenterofdata?Ifnot,why?
MULTIPLECHOICE.Choosetheonealternativethatbestcompletesthestatementoranswersthequestion.
5) OnarecentStatisticstest,thescoreswere61,66,68,82,84,86,88,90,92,and97.Findthe10%trimmedmean
ofthisdata.
A) 82 B) 77 C) 38.5 D) 85
Page27
6) Thelengthsofphonecallsfromonehousehold(inminutes)were2,4,6,7,and10minutes.Findthemidrange
forthisdata.
A) 6minutes B) 2minutes C) 10minutes D) 7minutes
7) Thecostoffivehomesinacertainareaisgiven.
$141,000 $149,000 $169,000 $139,000 $1,219,000
Whichmeasureofcentraltendencyshouldbeused?
A) median B) mean C) mode D) midrange
8) Thecostoffivehomesinacertainareaisgiven.
$186,000 $194,000 $214,000 $184,000 $1,264,000
Listanyoutlier(s).
A) $1,264,000 B) $186,000
C) $1,264,000and$186,000 D) Therearenooutliers.
9) Thecostoffivehomesinacertainareaisgiven.
$206,000 $214,000 $234,000 $204,000 $1,284,000
Calculatethemidrange.
A) $540,000 B) $214,000 C) $1,080,000 D) $428,400
2.4 MeasuresofVariation
1 FindMeasuresofVariation
MULTIPLECHOICE.Choosetheonealternativethatbestcompletesthestatementoranswersthequestion.
Provideanappropriateresponse.
1) Forthestem–and–leafplotbelow,findtherangeofthedataset.
Key:27=27
1
2
2
3
3
4
45
666789
77788999
01123445
6667889
03
A) 29 B) 43 C) 14 D) 37
Page28
2) Findtherangeofthedatasetrepresentedbythegraph.
A) 6 B) 17 C) 20 D) 5
3) Thegradepointaveragesfor10studentsarelistedbelow.Findtherangeofthedataset.
2.0 3.2 1.8 2.9 0.9 4.0 3.3 2.9 3.6 0.8
A) 3.2 B) 2.45 C) 1.4 D) 2.8
4) Theheights(ininches)of20adultmalesarelistedbelow.Findtherangeofthedataset.
70 72 71 70 69 73 69 68 70 71
67 71 70 74 69 68 71 71 71 72
A) 7 B) 5 C) 6 D) 6.5
5) Findthesamplestandarddeviation.
26159112214819
A) 7.1 B) 6.8 C) 2.1 D) 6.3
6) Findthesamplestandarddeviation.
1542537912142847
A) 17.8 B) 16.6 C) 29.1 D) 15.8
7) Findthesamplestandarddeviation.
2229212427282536
A) 4.8 B) 4.2 C) 1.6 D) 2.8
8) Theheights(ininches)of10adultmalesarelistedbelow.Findthesamplestandarddeviationofthedataset.
70 72 71 70 69 73 69 68 70 71
A) 1.49 B) 70 C) 3 D) 2.38
Page29
9) Sampleannualsalaries(inthousandsofdollars)forpublicelementaryschoolteachersarelisted.Findthe
samplestandarddeviation.
17.0 10.7 38.7 32.1 16.4 15.9
A) 10.97 B) 35.40 C) 3453.36 D) 2851.44
SHORTANSWER.Writethewordorphrasethatbestcompleteseachstatementoranswersthequestion.
10) Theheights(ininches)ofall10adultmalesinanofficearelistedbelow.Findthepopulationstandard
deviationandthepopulationvariance.
70 72 71 70 69 73 69 68 70 71
11) Inarandomsample,10studentswereaskedtocomputethedistancetheytravelonewaytoschooltothe
nearesttenthofamile.Thedataislistedbelow.Computetherange,standarddeviationandvarianceofthe
data.
1.1 5.2 3.6 5.0 4.8 1.8 2.2 5.2 1.5 0.8
2InterpretData
MULTIPLECHOICE.Choosetheonealternativethatbestcompletesthestatementoranswersthequestion.
Provideanappropriateresponse.
1) Withoutperforminganycalculations,usethestem–and–leafplotstodeterminewhichstatementisaccurate.
(i)

0
1
2
3
4
9
58
3377
25
1
(ii)

10
11
12
13
14
9
58
3377
25
1
(iii)

0
1
2
3
4
5
33337777
5
A) Datasets(i)and(ii)havethesamestandarddeviation.
B) Dataset(ii)hasthegreateststandarddeviation.
C) Dataset(i)hasthesmalleststandarddeviation.
D) Datasets(i)and(iii)havethesamerange.
Page30
2) Youareaskedtocomparethreedatasets.Withoutcalculating,determinewhichdatasethasthegreatest
samplestandarddeviationandwhichhastheleastsamplestandarddeviation.
(i)
(ii)
(iii)
A) Greatestsamplestandarddeviation:(i)
Leastsamplestandarddeviation:(iii)
B) Greatestsamplestandarddeviation:(i)
Leastsamplestandarddeviation:(ii)
C) Greatestsamplestandarddeviation:(iii)
Leastsamplestandarddeviation:(ii)
D) Greatestsamplestandarddeviation:(iii)
Leastsamplestandarddeviation:(i)
3) Youareaskedtocomparethreedatasets.Withoutcalculating,determinewhichdatasethasthegreatest
samplestandarddeviationandwhichhastheleastsamplestandarddeviation.
(i) (ii) (iii)
2
3
4
5
6
6
4
003399
8
1
2
3
4
5
6
4
00033399
8
2
3
4
5
6
6
45
0399
89
1
A) Greatestsamplestandarddeviation:(iii)
Leastsamplestandarddeviation:(ii)
B) Greatestsamplestandarddeviation:(iii)
Leastsamplestandarddeviation:(i)
C) Greatestsamplestandarddeviation:(i)
Leastsamplestandarddeviation:(ii)
D) Greatestsamplestandarddeviation:(i)
Leastsamplestandarddeviation:(iii)
Page31
3 CompareTwoDataSets
SHORTANSWER.Writethewordorphrasethatbestcompleteseachstatementoranswersthequestion.
Provideanappropriateresponse.
1) Youneedtopurchaseabatteryforyourcar.Therearetwotypesavailable.TypeAhasameanlifeoffiveyears
andastandarddeviationofoneyear.TypeBhasameanlifeoffiveyearsandastandarddeviationofone
month.Bothbatteriescostthesame.Whichoneshouldyoupurchaseifyouareconcernedthatyourcarwill
alwaysstart?Explainyourreasoning.
2) HerearethebattingaveragesofSammySosaandBarryBondsfor13recentyears.Whichplayerismore
consistent?Explainyourreasoning.
SammySosa 0.203 0.260 0.261
BarryBonds 0.292 0.311 0.336
0.300 0.268 0.273 0.251 0.308 0.288 0.320 0.328 0.288 0.279
0.312 0.294 0.308 0.291 0.303 0.262 0.306 0.328 0.370 0.341
3) Youarethemaintenanceengineerforalocalhighschool.Youmustpurchasefluorescentlightbulbsforthe
classrooms.ShouldyouchooseTypeAwithμ=3000hoursandσ=200hours,orTypeBwithμ=3000hours
andσ=250hours?
4 UsetheEmpiricalRule
MULTIPLECHOICE.Choosetheonealternativethatbestcompletesthestatementoranswersthequestion.
Provideanappropriateresponse.
1) ThemeanIQscoreofadultsis100,withastandarddeviationof15.UsetheEmpiricalRuletofindthe
percentageofadultswithscoresbetween70and130.(Assumethedatasethasabell –shapeddistribution.)
A) 95% B) 68% C) 99.7% D) 100%
2) Themeanscoreofaplacementexamforentranceintoamathclassis80,withastandarddeviationof10.Use
theEmpiricalRuletofindthepercentageofscoresthatliebetween60and80.(Assumethedatasethasa
bell–shapeddistribution.)
A) 47.5% B) 68% C) 34% D) 95%
3) ThemeanIQscoreofstudentsinaparticularcalculusclassis110,withastandarddeviationof5.Usethe
EmpiricalRuletofindthepercentageofstudentswithanIQabove120.(Assumethedatasethasabell –shaped
distribution.)
A) 2.5% B) 11.15% C) 13.5% D) 15.85%
4) Themeanscoreofacompetencytestis65
,
withastandarddeviationof4.UsetheEmpiricalRuletofindthe
percentageofscoresbetween53and77.(Assumethedatasethasabell–shapeddistribution.)
A) 99.7% B) 50% C) 68% D) 95%
5) Themeanscoreofacompetencytestis82,withastandarddeviationof2.Betweenwhattwovaluesdoabout
99.7%ofthevalueslie?(Assumethedatasethasabell–shapeddistribution.)
A) Between76and88 B) Between80and84 C) Between78and86 D) Between74and90
6) Themeanlengthofahumanpregnancyis266 days,withastandarddeviationof9days.UsetheEmpirical
Ruletodeterminethepercentageofwomenwhosepregnanciesarebetween257and275days.(Assumethe
datasethasabell–shapeddistribution.)
A) 68% B) 50% C) 95% D) 99.7%
Page32
7) ThemeanSATverbalscoreis462
,
withastandarddeviationof98.UsetheEmpiricalRuletodeterminewhat
percentofthescoresliebetween462and560.(Assumethedatasethasabell–shapeddistribution.)
A) 34% B) 68% C) 49.9% D) 47.5%
8) ThemeanSATverbalscoreis486
,
withastandarddeviationof95.UsetheEmpiricalRuletodeterminewhat
percentofthescoresliebetween391and486.(Assumethedatasethasabell–shapeddistribution.)
A) 34% B) 68% C) 49.9% D) 47.5%
9) ThemeanSATverbalscoreis500
,
withastandarddeviationof100.UsetheEmpiricalRuletodeterminewhat
percentofthescoresliebetween500and700.(Assumethedatasethasabell–shapeddistribution.)
A) 47.5% B) 68% C) 34% D) 49.9%
10) ThemeanSATverbalscoreis490
,
withastandarddeviationof96.UsetheEmpiricalRuletodeterminewhat
percentofthescoresliebetween298and586.(Assumethedatasethasabell–shapeddistribution.)
A) 81.5% B) 68% C) 34% D) 83.9%
11) Themeanmonthlyrentforasampleofstudioapartmentsinonecityis$1200 withastandarddeviationof
$210.Themonthlyrentsforeightmorestudioapartmentsinthecityarelisted.Usingthesamplestatistics
above,determinewhichofthedatavaluesareunusual.Areanyofthedatavaluesveryunusual?Explain.
(Assumethedatasethasabell–shapeddistribution.)
$1074,$1536,$1641,$528,$801,$1662,$1347,$696
A) $1641
,
$528
,
$1662
,
$696areunusualbecausetheyaremorethan2standarddeviationsfromthemean.
$528isveryunusualbecauseitismorethan3standarddeviationsfromthemean.
B) $1536
,
$1641
,
$528
,
$801
,
$1662
,
$696 areunusualbecausetheyaremorethan1standarddeviationfrom
themean.$1641,$528,$1662,$696areveryunusualbecausetheyaremorethan2standarddeviations
fromthemean.
C) $528isunusualbecauseitismorethan3standarddeviationsfromthemean.Therearenovaluesthatare
veryunusualbecausenovalueismorethan4standarddeviationsfromthemean.
D) $1641
,
$528
,
$801
,
$1662
,
$696areunusualbecausetheyaremorethan2standarddeviationsfromthe
mean.$528and$696areveryunusualbecausetheyaremorethan3standarddeviationsfromthemean.
5 UseChebychevʹsTheorem
SHORTANSWER.Writethewordorphrasethatbestcompleteseachstatementoranswersthequestion.
Provideanappropriateresponse.
1) Heightsofadultwomenhaveameanof63.6in.andastandarddeviationof2.5in.DoesChebyshevʹsTheorem
sayaboutthepercentageofwomenwithheightsbetween58.6in.and68.6in.?
2) Heightsofadultwomenhaveameanof63.6in.andastandarddeviationof2.5in.ApplyChebyshevʹs
Theoremtothedatausingk=3.Interprettheresults.
Page33
6 UseGroupedDatatoCalculateaMeanandStandardDeviation
MULTIPLECHOICE.Choosetheonealternativethatbestcompletesthestatementoranswersthequestion.
Usethegroupeddataformulastofindtheindicatedmeanorstandarddeviation.
1) Thesalariesofarandomsampleofacompanyʹsemployeesaresummarizedinthefrequencydistribution
below.Approximatethesamplemean.
Salary($) Employees
5,001–10,000 16
10,001–15,000 14
15,001–20,000 11
20,001–25,000 16
25,001–30,000 23
A) $18,500.50 B) $17,500 C) $20,350.55 D) $16,650.45
2) Thespeedsofarandomsampleof100carsarerecordedastheypassahighwaycheckpoint.Theresultsare
summarizedinthefrequencydistributionbelow.Approximatethesamplemean.
Speed(mph) Cars
30–39 3
40–49 17
50–59 50
60–69 19
70–79 11
A) 56.3mph B) 54.5mph C) 61.9 mph D) 59.1 mph
3) Themanagerofabankrecordedtheamountoftimearandomsampleofcustomersspentwaitinginline
duringpeakbusinesshoursoneMonday.Thefrequencydistributionbelowsummarizestheresults.
Approximatethesamplemean.Roundyouranswertoonedecimalplace.
Waitingtime
(minutes)
Numberof
customers
0–312
4–714
8–11 13
12–15 6
16–19 8
20–23 2
24–27 1
A) 9.1min B) 13.5min C) 8.0 min D) 9.2 min
Page34
4) Theheightsofarandomsampleofprofessionalbasketballplayersaresummarizedinthefrequency
distributionbelow.Approximatethesamplemean.Roundyouranswertoonedecimalplace.
Height(in.) Frequency
70–71 1
72–73 6
74–75 8
76–77 12
78–79 9
80–81 5
82–83 2
A) 76.6in. B) 13.5in. C) 74.9 in. D) 78.4 in.
5) Arandomsampleof30highschoolstudentsisselected.Eachstudentisaskedhowmanyhoursheorshe
spentontheInternetduringthepreviousweek.Theresultsareshowninthehistogram.Estimatethesample
mean.
A) 7.9hr B) 7.7hr C) 8.1hr D) 8.3hr
6) Arandomsampleof25communityserviceprojectsisselectedandthescoresarerecorded.Theresultsare
showninthehistogram.Estimatethesamplemean.
A) 97.1 B) 97.3 C) 96.9 D) 96.7
Page35
7) Forthefollowingdataset,approximatethesamplestandarddeviation.
Miles(perday) Frequency
1–29
3–422
5–628
7–815
9–10 4
A) 2.1 B) 5.1 C) 2.9 D) 1.6
8) Forthefollowingdataset,approximatethesamplestandarddeviation.
Phonecalls(perday) Frequency
8–11 18
12–15 23
16–19 38
20–23 47
24–27 32
A) 5.1 B) 18.8 C) 2.9 D) 3.2
9) Forthefollowingdataset,approximatethesamplestandarddeviation.
Height(ininches) Frequency
50–52 5
53–55 8
56–58 12
59–61 13
62–64 11
A) 3.85 B) 1.86 C) 2.57 D) 0.98
10) Arandomsampleof30highschoolstudentsisselected.Eachstudentisaskedhowmanyhoursheorshe
spentontheInternetduringthepreviousweek.Theresultsareshowninthehistogram.Estimatethesample
standarddeviation.
A) 2.4hr B) 2.2hr C) 2.6hr D) 2.0hr
Page36
7 UseFormulastoAnalyzeData
SHORTANSWER.Writethewordorphrasethatbestcompleteseachstatementoranswersthequestion.
Provideanappropriateresponse.
1) Forthedatabelow,findPearsonʹsindexofskewness.Thedataset:Thesystolicbloodpressuresof20randomly
selectedpatientsatabloodbank.
130 120 115 132 136 124 119 145 98 110
125 120 115 130 140 105 116 121 125 108
MULTIPLECHOICE.Choosetheonealternativethatbestcompletesthestatementoranswersthequestion.
2) Inarandomsample,10studentswereaskedtocomputethedistancetheytravelonewaytoschooltothe
nearesttenthofamile.Thedataislistedbelow.
a)Ifaconstantvaluekisaddedtoeachvalue,howwillthestandarddeviationbeaffected?
b)Ifeachvalueismultipliedbyaconstantk,howwillthestandarddeviationbeaffected?
1.1 5.2 3.6 5.0 4.8 1.8 2.2 5.2 1.5 0.8
A) Thestandarddeviationwillnotbeaffected.
B) Thestandarddeviationwillbemultipliedbytheconstantk.
8 ComputetheCoefficientofVariation
SHORTANSWER.Writethewordorphrasethatbestcompleteseachstatementoranswersthequestion.
Provideanappropriateresponse.
1) Inarandomsample,10studentswereaskedtocomputethedistancetheytravelonewaytoschooltothe
nearesttenthofamile.Thedataislistedbelow.Computethecoefficientofvariation.
1.1 5.2 3.6 5.0 4.8 1.8 2.2 5.2 1.5 0.8
MULTIPLECHOICE.Choosetheonealternativethatbestcompletesthestatementoranswersthequestion.
Findthecoefficientofvariationforeachofthetwosetsofdata,thencomparethevariation.Roundresultstoone
decimalplace.
2) Listedbelowarethesystolicbloodpressures(inmmHg)forasampleofmenaged20–29andforasampleof
menaged60–69.
Menaged20–29: 118 124 129 118 131 123
Menaged60–69: 131 151 137 125 164 139
A) Menaged20–29:4.4%
Menaged60–69:10.0%
Thereissubstantiallymorevariationinbloodpressuresofthemenaged60–69.
B) Menaged20–29:4.6%
Menaged60–69:10.5%
Thereissubstantiallymorevariationinbloodpressuresofthemenaged60–69.
C) Menaged20–29:4.2%
Menaged60–69:8.1%
Thereissubstantiallymorevariationinbloodpressuresofthemenaged60 –69.
D) Menaged20–29:7.2%
Menaged60–69:4.6%
Thereismorevariationinbloodpressuresofthemenaged20–29.
Page37
3) Thecustomerservicedepartmentofaphonecompanyisexperimentingwithtwodifferentsystems.On
Mondaytheytrythefirstsystemwhichisbasedonanautomatedmenusystem.OnTuesdaytheytrythe
secondsysteminwhicheachcallerisimmediatelyconnectedwithaliveagent.Aqualitycontrolmanager
selectsasampleofsevencallseachday.Herecordsthetimeforeachcustomertohavehisorherquestion
answered.Thetimes(inminutes)arelistedbelow.
AutomatedMenu: 11.2 7.2 4.0 2.9 9.2 6.3 5.5
Liveagent: 6.3 2.5 4.8 4.1 3.4 5.2 3.7
A) AutomatedMenu:43.7%
Liveagent:29.4%
Thereissubstantiallymorevariationinthetimesfortheautomatedmenusystem.
B) AutomatedMenu:45.3%
Liveagent:30.5%
Thereissubstantiallymorevariationinthetimesfortheautomatedmenusystem.
C) AutomatedMenu:46.9%
Liveagent:31.5%
Thereissubstantiallymorevariationinthetimesfortheautomatedmenusystem.
D) AutomatedMenu:24.3%
Liveagent:46.2%
Thereissubstantiallymorevariationinthetimesfortheliveagent.
4) Comparethevariationinheightstothevariationinweightsofthirteen–yearoldgirls.Theheights(ininches)
andweights(inpounds)ofninerandomlyselectedthirteen–yearoldgirlsarelistedbelow.
Heights(inches): 59.3 61.2 62.6 64.7 60.1 58.3 64.6 63.7 66.1
Weights(pounds): 86 97 93 119 96 90 123 98 139
A) Heights:4.3%
Weights:17.2%
Thereissubstantiallymorevariationintheweightsthanintheheightsofthegirls.
B) Heights:4.1%
Weights:16.4%
Thereissubstantiallymorevariationintheweightsthanintheheightsofthegirls.
C) Heights:3.9%
Weights:15.4%
Thereissubstantiallymorevariationintheweightsthanintheheightsofthegirls.
D) Heights:11.5%
Weights:6.5%
Thereissubstantiallymorevariationintheheightsthanintheweightsofthegirls.
2.5 MeasuresofPosition
1 CreateorInterpretaBox–and–whiskerPlot
MULTIPLECHOICE.Choosetheonealternativethatbestcompletesthestatementoranswersthequestion.
Provideanappropriateresponse.
1) Thetestscoresof30studentsarelistedbelow.Findthefive–numbersummary.
31 41 45 48 52 55 56 58 63 65
67 67 69 70 70 74 75 78 79 79
80 81 83 85 85 87 90 92 95 99
A) Min=31,Q1=58,Q2=72,Q3=83,Max=99 B) Min=31,Q1=58,Q2=70,Q3=83,Max=99
C) Min=31,Q1=57,Q2=70,Q3=81,Max=99 D) Min=31,Q1=57,Q2=72,Q3=81,Max=99
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2) Theweights(inpounds)of30preschoolchildrenarelistedbelow.Findthefive–numbersummary.
25 25 26 26.5 27 27 27.5 28 28 28.5
29 29 30 30 30.5 31 31 32 32.5 32.5
33 33 34 34.5 35 35 37 37 38 38
A) Min=25,Q1=28,Q2=30.75,Q3=34,Max=38
B) Min=25,Q1=28,Q2=30.5,Q3=34,Max=38
C) Min=25,Q1=27.5,Q2=30.75,Q3=33,Max=38
D) Min=25,Q1=27.5,Q2=30.5,Q3=33.5,Max=38
SHORTANSWER.Writethewordorphrasethatbestcompleteseachstatementoranswersthequestion.
3) Theweights(inpounds)of30preschoolchildrenarelistedbelow.Findtheinterquartilerangeofthe30
weightslistedbelow.Whatcanyouconcludefromtheresult?
25 25 26 26.5 27 27 27.5 28 28 28.5
29 29 30 30 30.5 31 31 32 32.5 32.5
33 33 34 34.5 35 35 37 37 38 38
MULTIPLECHOICE.Choosetheonealternativethatbestcompletesthestatementoranswersthequestion.
4) Thecholesterollevels(inmilligramsperdeciliter)of30adultsarelistedbelow.Findtheinterquartilerangefor
thecholesterollevelofthe30adults.
154 156 165 165 170 171 172 180 184 185
189 189 190 192 195 198 198 200 200 200
205 205 211 215 220 220 225 238 255 265
A) 31 B) 30 C) 211 D) 180
5) Thecholesterollevels(inmilligramsperdeciliter)of30adultsarelistedbelow.FindQ1.
154156165165170171172180184185
189189190192195198198200200200
205205211215220220225238255265
A) 180 B) 200 C) 184.5 D) 171
6) Usethedatatoidentifyanyoutliers.
35 40 54 65 67
69 71 73 74 76
80 82 87 90 99
A) 35
,
40 B) 35
,
99 C) 35 D) None
7) Usethedatatoidentifyanyoutliers.
16 25 133 15
518 820 14
17 19 16 10 21
28 14 37 18
A) 1,33
,
37 B) 1,37 C) 33
,
37 D) None
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8) Usethedatatoidentifyanyoutliers.
15 18 18 19 22 23 24
24 24 24 25 26 26 27
28 28 30 32 33 40 42
A) 40,42 B) 42 C) 15,42 D) None
SHORTANSWER.Writethewordorphrasethatbestcompleteseachstatementoranswersthequestion.
9) Thetestscoresof30studentsarelistedbelow.Drawabox–and–whiskerplotthatrepresentsthedata.
31 41 45 48 52 55 56 56 63 65
67 67 69 70 70 74 75 78 79 79
80 81 83 85 85 87 90 92 95 99
10) Thecholesterollevels(inmilligramsperdeciliter)of30adultsarelistedbelow.Drawabox–and–whiskerplot
thatrepresentsthedata.
154 156 165 165 170 171 172 180 184 185
189 189 190 192 195 198 198 200 200 200
205 205 211 215 220 220 225 238 255 265
MULTIPLECHOICE.Choosetheonealternativethatbestcompletesthestatementoranswersthequestion.
11) Usethebox–and–whiskerplotbelowtodeterminewhichstatementisaccurate.
A) Onehalfofthecholesterollevelsarebetween180and211.
B) Onehalfofthecholesterollevelsarebetween180and197.5.
C) About25%oftheadultshavecholesterollevelsofatmost211.
D) About75%oftheadultshavecholesterollevelslessthan180.
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2 CalculateorComparez–scores
SHORTANSWER.Writethewordorphrasethatbestcompleteseachstatementoranswersthequestion.
Provideanappropriateresponse.
1) ThemidpointsA,B,andCaremarkedonthehistogram.Withoutcalculating,matchthemwiththeindicated
z–scores.Whichz–scores,ifany,wouldbeconsideredunusual?
z=0
z=-1.33
z=2.01
MULTIPLECHOICE.Choosetheonealternativethatbestcompletesthestatementoranswersthequestion.
2) Findthez–scoreforthevalue62
,
whenthemeanis79 andthestandarddeviationis4.
A) z=-4.25 B) z=-4.50 C) z=-0.73 D) z=0.73
3) Manyfirmsuseon–the–
j
obtrainingtoteachtheiremployeescomputerprogramming.Supposeyouworkin
thepersonneldepartmentofafirmthatjustfinishedtrainingagroupofitsemployeestoprogram,andyou
havebeenrequestedtoreviewtheperformanceofoneofthetraineesonthefinaltestthatwasgiventoall
trainees.Themeanandstandarddeviationofthetestscoresare81and3,respectively,andthedistributionof
scoresisbell–shapedandsymmetric.Supposethetraineeinquestionreceivedascoreof77.Computethe
traineeʹsz–score.
A) z=-1.33 B) z=1.33 C) z=-0.91 D) z=0.91
4) Aradiostationclaimsthattheamountofadvertisingperhourofbroadcasttimehasanaverageof17 minutes
andastandarddeviationequalto2.7minutes.Youlistentotheradiostationfor1hour,atarandomlyselected
time,andcarefullyobservethattheamountofadvertisingtimeisequalto11minutes.Calculatethez–scorefor
thisamountofadvertisingtime.
A) z=-2.22 B) z=2.22 C) z=-0.49 D) z=0.49
SHORTANSWER.Writethewordorphrasethatbestcompleteseachstatementoranswersthequestion.
5) Testscoresforahistoryclasshadameanof79withastandarddeviationof4.5.Testscoresforaphysicsclass
hadameanof69withastandarddeviationof3.7.Supposeastudentgetsa65onthehistorytestanda74on
thephysicstest.Calculatethez–scoreforeachtest.Onwhichtestdidthestudentperformbetter?
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MULTIPLECHOICE.Choosetheonealternativethatbestcompletesthestatementoranswersthequestion.
6) ForthemathematicspartoftheSATthemeanis514withastandarddeviationof113,andforthemathematics
partoftheACTthemeanis20.6withastandarddeviationof5.1.Bobscoresa660ontheSATanda27onthe
ACT.Usez–scorestodetermineonwhichtestheperformedbetter.
A) SAT B) ACT
7) Thebirthweightsfortwinsarenormallydistributedwithameanof2353gramsandastandarddeviationof
647grams.Usez–scorestodeterminewhichbirthweightcouldbeconsideredunusual.
A) 3647g B) 1200g C) 2000g D) 2353g
3 FindtheMidquartile
MULTIPLECHOICE.Choosetheonealternativethatbestcompletesthestatementoranswersthequestion.
Provideanappropriateresponse.
1) Theagesof10groomsattheirfirstmarriagearelistedbelow.Findthemidquartile.
35.1 24.3 46.6 41.6 32.9 26.8 39.8 21.5 45.7 33.9
A) 34.2 B) 43.7 C) 34.1 D) 34.5
4 FindaPercentile
MULTIPLECHOICE.Choosetheonealternativethatbestcompletesthestatementoranswersthequestion.
Provideanappropriateresponse.
1) Thegraphbelowisanogiveofscoresonamathtest.
PercentileRanksofMathTestScores
10 20 30 40 50 60 70 80 90 100
100
90
80
70
60
50
40
30
20
10
Test Score
Percentile
10 20 30 40 50 60 70 80 90 100
100
90
80
70
60
50
40
30
20
10
Test Score
Percentile
Usethegraphtoapproximatethepercentilerankofanindividualwhosetestscoreis70.
A) 53 B) 80 C) 58 D) 75
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2) Thegraphbelowisanogiveofscoresonamathtest.
PercentileRanksofMathTestScores
10 20 30 40 50 60 70 80 90 100
100
90
80
70
60
50
40
30
20
10
Test Score
Percentile
10 20 30 40 50 60 70 80 90 100
100
90
80
70
60
50
40
30
20
10
Test Score
Percentile
Usethegraphtoapproximatethetestscorethatcorrespondstothe10thpercentile?
A) 40 B) 1 C) 34 D) 6
3) Thecholesterollevels(inmilligramsperdeciliter)of30adultsarelistedbelow.Findthepercentilethat
correspondstoacholesterollevelof238milligramsperdeciliter.
154 156 165 165 170 171 172 180 184 185
189 189 190 192 195 198 198 200 200 200
205 205 211 215 220 220 225 238 255 265
A) 90thpercentile B) 30thpercentile C) 40thpercentile D) 50thpercentile
4) Thetestscoresof30studentsarelistedbelow.Findthepercentilethatcorrespondstoascoreof74.
31 41 45 48 52 55 56 56 63 65
67 67 69 70 70 74 75 78 79 79
80 81 83 85 85 87 90 92 95 99
A) 50thpercentile B) 90thpercentile C) 30thpercentile D) 40thpercentile
5) Thetestscoresof30studentsarelistedbelow.Whichtestscoresareabovethe75thpercentile?
31 41 45 48 52 55 56 56 63 65
67 67 69 70 70 74 75 78 79 79
80 81 83 85 85 87 90 92 95 99
A) 85,85,87,90,92,95,99 B) 90,92,95,99
C) 83,85,85,87,90,92,95,99 D) 87,90,92,95,99
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6) Theweights(inpounds)of30preschoolchildrenarelistedbelow.Whichweightsarebelowthe25th
percentile?
25252626.5272727.5282828.5
2929303030.531313232.532.5
33333434.5353537373838
A) 25,25,26,26.5,27,27,27.5 B) 25,25,26,26.5,27,27,27.5,28,28
C) 25,25,26,26.5,27,27 D) 25,25,26,26.5
7) Ateachergivesa20–pointquizto10students.Thescoresarelistedbelow.Whatpercentilecorrespondstothe
scoreof12?
20 810 715 16 12 19 14 9
A) 40 B) 13 C) 25 D) 12
8) Inadatasetwithaminimumvalueof54.5andamaximumvalueof98.6with300observations,thereare186
pointslessthan81.2.Findthepercentilefor81.2.
A) 62 B) 71 C) 68 D) 53
9) Thecholesterollevels(inmilligramsperdeciliter)of30adultsarelistedbelow.Findthepercentilethat
correspondstocholesterollevelof195.
154 156 165 165 170 171 172 180 184 185
189 189 190 192 195 198 198 200 200 200
205 205 211 215 220 220 225 238 255 265
A) 50 B) 12 C) 33 D) 58
5 Concepts
SHORTANSWER.Writethewordorphrasethatbestcompleteseachstatementoranswersthequestion.
Provideanappropriateresponse.
1) AstudentʹsscoreontheSAT–1placementtestforU.S.historyisinthe90thpercentile.Whatcanyouconclude
aboutthestudentʹstestscore?
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Ch.2 DescriptiveStatistics
AnswerKey
2.1 FrequencyDistributionsandTheirGraphs
1 InterpretaFrequencyDistribution
2 InterpretFrequencyDistributionGraphs
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4 Concepts
2.2 MoreGraphsandDisplays
1 InterpretDataSets
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2 GraphDataSets
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2.3 MeasuresofCentralTendency
1 InterprettheGraphofaDistribution
2 FindtheMean,Median,andMode
3FindtheWeightedMean
4 FindtheMeanofFrequencyDistribution
5 Concepts
2.4 MeasuresofVariation
1 FindMeasuresofVariation
2 InterpretData
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3 CompareTwoDataSets
4 UsetheEmpiricalRule
5 UseChebychevʹsTheorem
6 UseGroupedDatatoCalculateaMeanandStandardDeviation
7 UseFormulastoAnalyzeData
8 ComputetheCoefficientofVariation
2.5 MeasuresofPosition
1 CreateorInterpretaBox–and–whiskerPlot
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2 CalculateorComparez–scores
3 FindtheMidquartile
4 FindaPercentile
5 Concepts
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