Math 111 practice test chapter 12 answers PDF

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Math111 Chapter12PracticeTest 1. IfIwantedtosurvey50CabriniCollegestudentsaboutwheretheyprefertoeatoncampus,which wouldbethemostappropriatewaytoconductmysurvey? a. Find50peopleinthecafeteriaandaskthem. b. Find25peopleinthecafeteriaand25peopleinJazzman’s. c. Randomlysurveydifferentclasses.  2. A____sample_____isasubsetofthepopulation. 3. Constructafrequencydistributionforthedataofthegradesof25studentstakingMath11last semester:A,C,D,B,A,A,C,F,B,C,A,D,B,B,D,C,B,C,B,D,A,F,B,C,B A 5 B 8 C 6 D 4 F 2 4. TheaverageageoftheCabriniCollegestudenthaschangedovertheyears.Theagesof25 randomlyselectedstudentsareasfollows:17,19,20,37,21,18,44,22,18,25,29,48,24,19,30, 27,18,36,20,46,52,21,22,36,18. Constructagroupedfrequencydistributionforthedata.Usetheclasses:under20,21‐30,31– 40,41‐50,over50. Under20 ||||||||| 9 21‐30 ||||||||| 9 31‐40 ||| 3 41‐50 ||| 3 Over50 | 1 5. Makeahistogramfortheabovedata:          6. Createastemandleafplotfortheabovedata: 1 7,8,8,8,8,9,9 2 3 4 5

0,0,1,1,2,2,4,5,7,9 0,6,6,7 4,6,8 2

 Matchthedescriptiontothemeasureofcentraltendency. 7. 8. 9. 10.

Mean ___C_____ Median ___D_____ Mode ___B_____ Midrange___A____

   

   

   

   

a.foundbyaddingthelowestandhighestdatavaluesanddividingby2. b.thedatavaluethatoccursmostofteninadataset. c.obtainedbyaddingallthedataitemsthendividingthesumbythenumberofitems. d.themiddle‐mostdatavalueinanorderedlist;iftherearetwovalues,youwouldtakethemea 11. AlotofCabriniCollegestudentsgohomeontheweekends.Forsome,thisisalongertripthanfor others.Weasked10randomlyselectedstudentshowmanymilesitistohome. 21,6,13,36,22,48,104,73,158,17 Findthemeandistanceofthissample: (21+6+13+36+22+48+104+73+158+17)/10=49.8Miles  12. Findthemediandistanceofthesample: 6,13,17,21,22,26,48,73,104,158 Median=(22+26)/2=24Miles 13. Forthefrequencydistribution,givethemedian: testscores 100 90s 80s 70s 60s >50 Numberofstudents (withthatgrade)

3

5

7

10

3

1

Totalnumberofstudents:n=29 (29+1)/2=15thposition,sointhe80s:3+5=8;keepgoing.8+7=15;ourmedianscoreisinthe 80’s  14. Findthemodeofthesamedata: 70’s;therewere10gradesinthe70’s.Thisismorethananyotherrange. 

15. The___range___isthedifferencebetweenthehighestandlowestdatavaluesinaset;indicatesthe totalspreadofthedata. 16. 94,62,88,85,95,90,85,100,85,91 Findthemeananddeviationsforthedata(only deviations.Notstandarddeviationyet): (94+62+88+85+95+90+85+100+85+91)/10=87.5isthemean Deviations: 6.5,‐25.5,0.5,‐2.5,7.5,2.5,‐2.5,12.5,‐2.5,3.5 17. __0__isalwaysthesumofthedeviationsforasetofdata. 18. Computethestandarddeviationfortheabovedata: SumofDev2=942.5 DataItem Deviation Dev2 100 12.5 156.25  95 7.5 56.25 SD^  Standarddeviation= 94 6.5 42.25  91 90 88 85 85 85 62

3.5 2.5 0.5 ‐2.5 ‐2.5 ‐2.5 ‐25.5

12.25 6.25 .25 6.25 6.25 6.25 650.25

=

. 



=√104.72 =10.23    19. Saytwosections(AandB)ofMath111takethesametest.Theirmeansarethesame,butsection A’sstandarddeviationis4timesthesizeofB’sstandarddeviation.Whatdoyouthinkthismeans? (i.e.Whichclasshasmorestudentsonthesamelevel?) __SectionBhasasmallerstandarddeviation,sothestudentsgotscoresclosertogether. Thatmeanstheymostlyknowthesamethings,orthey’reonthesameleveloflearning,etc.___ 20. Abellcurve,oranormaldistribution,issymmetric.  21. IfthemeanSATscoreforagroupofhighschoolseniorsis800andastandarddeviationof150,find thescorethatis a. 2standarddeviationsbelowthemean: 150*2=300.800‐300=500 b. 3standarddeviationsabovethemean: 150*3=450.800+450=1250 c. TheRANGEofscoresbetween3standarddeviationsbelowand1standarddeviation above: 150*3=450.800‐450=350AND150*1=150.800+150=950 950‐350=600  22. Az‐scoredescribeshowmanystandarddeviationsadataiteminanormaldistributionlies aboveorbelowthemean.

 23. Whenadatavalueisabovethemean,ithasapositivez‐score.  24. JoetakesatestinBiologyandMath.Eachtesthasdatavaluesthatarenormallydistributed.He scoresan85%onhisBiologytestandan80%onhisMathtest.ThemeangradefortheBiologytest is88%withastandarddeviationof3.ThemeangradefortheMathtestis78%withastandard deviationof2.WhichtestdidJoedobetterinwithrespecttotherestoftheclass?    =  =‐1   

ForBiology:zscore= ForMath:zscore=

25.

26.

27.

28.



= =1 

JoedidbetteronhisMathtestthanonhisBiologytest,sincehedidbetterthanaverageinMath, butnotBiology.  IfIdidbetterthan60%ofthestudentstakingtheSAT,whatwasmypercentile? 60thpercentile  IfIdidworsethan27%ofthestudentstakingtheSAT,whatwasmypercentile? 73rdpercentile  The25thpercentileisthefirstquartile,the50thpercentileisthesecond,andthe75thpercentile isthethird.  InasurveyofCabriniCollegestudents,itwasfoundthattheaveragenumberofnightsspent partyingintheschoolyearwas40.Thedatawasnormallydistributedandhadastandarddeviation of5.Usingthetable,findthepercentileofstudentswhopartylessthan50nightsinaschoolyear. zscorefor50nightsofpartying:

  =  =2 

97.72 percentile.  29. Itookasurveyofarandomsampleof25people.Whatismymarginoferror? Themarginoferroris      



√



= 

NumberofSyllablesin JapaneseWords 30. Giventhehistogram,answerthefollowing questions:  a. Isthehistogramnormal,skewed totheright,orskewedtotheleft? SkewedRight b. Findthemean,median,andmode forthenumberofsyllablesinthe sampleofJapanesewords. Mean:2.1=

NumberofWords



40

34

30

18

20

9

10

2

0

󰇛󰇜󰇛󰇜󰇛󰇜󰇛󰇜󰇛󰇜󰇛󰇜 

36

1

2

3

4

5

1

NumberofWords

6

NumberofSyllables



 Median:2 Mode:1(hasthehighestfrequency) c. Arethemeasuresofcentraltendencyfrompart(b)consistentwiththeshapeofthe distributionthatyoudescribedinpart(a)?Explain. Yes.Themeanisgreaterthanthemedian,sothehistogramwouldbeskewedtothe right.  ...