概率論與數(shù)理統(tǒng)計第三課后答案習題

1、leadingcadresawarenessofrightinplacestudythepartyConstitutionpartyrulesseriesofspeechescanmakepropereffect.Partycadresto“two“l(fā)eadbyexampletoleadbyexamplewemustchangeourmindrecognizingthat“two“isimptant.FirstlearntheCommu

2、nistPartyConstitutionPartyruleslearninglearningseriesimptantspeechbyGeneralSecretarycanenhancethey.Withthe“thirdrevolution“theriseofrapidchangesinourlifearefeelingtheCommunistsshouldadheretothetheyofconfidencewillcontinu

3、etolearnfromthevoicesofthetimesthetimesinturnwillhavenewrequirementsfleadingpartycadres.“Two“isthemostbasicmeaningofmembersallmasteringthecetheythemostadvancedweaponstheycomplementthespiritofcalcium.SecondlytheCommunistP

4、artyConstitutionPartyruleslearninglearningseriesimptantspeechbyGeneralSecretarybeabletofirmlybuildtheideologicalfoundation.Undertheimpactofmultiplevaluesthe“two“istohelpcultivateindependentjudgmentinnumerousmiscellaneous

5、multipleconceptssothatthemajityconsensusofpartymemberstheimptantmagicweaponofthepartywiththeresonancefrequency.FinallytheConstitutionoftheCommunistPartypartyruleslearninglearningseriesimptantspeechcanstcrowdsGeneralSecre

6、taryposition.Nowsomegrassrootswkinthe“theoldwaydidntwkhardwaycannotthenewapproachwouldnot“phenomenonsometimesduetoamassofpartymemberscadresnotunderstingdoesnotmeet.Infactthemass“convincing““identity“Behindarelikelytobepa

7、rtymembersleadingcadresthemselvesigningbeliefsheldresultinginlackofpersuasionsenseofidentity.“Two“isinfactguaranteedpartycadreswkanimptantprerequisitefconvincingthemasses.Baconsaiditwell:“practicalmencanhleindividualmatt

8、ersbutlookingatthewholeoperationgloballybutonlymancandotoknowledge.“Givingup“two“effectivemustfirstraiseawarenessofleadingcadresofpartymembersaspartymemberslearnrealresponsibility“toknow“to“music““good“changesinparallelw

9、iththegrounddonotfgettoalsoanswertheantennadrawcatchesonmeteologywhichsitbetweenheavenEarthwhichmeldstogetherthedreamsofpracticingCommunist.Memberscadresshouldin“twolearnado“inthebasedpostdocontributioninallmembersinthec

10、arriedout“l(fā)earnConstitutionPartyruleslearnseriesspeechdoqualifiedmembers“l(fā)earningeducationthisisfollowingpartyofmasslineeducationpracticeactivities“threestrictthreereal“topiceducationzhihoudeepeningpartyeducationofonceim

11、ptantpracticeispromoted“threestrictthreereal“topiceducationfrom“keyminity“toallmembersexpfromconcentratededucationtoregulareducationextendsofimptantinitiatives.Vastnumbersofpartymemberscadresinthecourseoftwoshouldbebased

12、ontheiractualstrivingtobe“l(fā)earning““done“markers.Strengtheningtheeticalstudybelieffaith.Theyisanactionguideonlytheeticalknowledgeinplacetounityactioncanconsciously.Constitutionisthefundamentallawofthepartypartyrulesarepa

13、rtymustfollowtheGeneralrules.StudyingimplementingthepartyConstitutionPartyrulesaseriesofimptantspeechGeneralSecretaryisaguidetopersistingdevelopingsocialismwithChineseacteristicsisabasicwkofstrengtheningthepartysconstruc

14、tionbutalsoeacheveryCommunistPartyMembersobligationssolemnresponsibility.Theseimptantcontentfeachpartymustknowwouldbelievewilldoboth.WeGeneralSecretaryofthepartyConstitutionaseriesofremarkswithholdgraspthereal“l(fā)earning“t

15、hatbasisbasedontheConstitutionspeaktoissueinaccdancewiththeserieschangedtheproblem.Seconddisciplinedinlinetobecomelawabidingmodel.Isnotnorules.Ifthereisnoirondisciplinepartymemberscadreswillbecomeamessitwillloseitsfighti

16、ngstrengthvitalitypuritynaturallymuchlessadvanced.By“two“educationpartymemberscadrestokeepthe“bottomline“nottheme“redlines“consciouslypracticethe“threeSuns“consciouslyactaccdingtotheConstitutionpartyrulesremainsapolitica

17、lfcetoperfmpartyoathatreeofitsownimage.Threeistheloyaldaretoplayplaytopartymembers.LearningistheFoundationisthekeytodevelopmentisthegoal.“Two“mainobjectiveistoletthemajityoftheplaytotheexemplaryroleofpartymemberscadrespa

18、rtyConstitutionpartyrulestoexamine.Tousenewcriteriatoguideourbehavi.Througheducationtheidealconvictionkeepinmindthatmembershiplearnlearnlearngoplayavanguardexemplaryrolethecouragetoplayasalwaysmaintainthepioneerpioneerin

19、genterprisingspiritconstantlyimproveourowncapacitylevelofserviceaccdingtopositionsmakecontributions.Heartschangeleadmestrict“beganintheknowknowasLukeSkywalker““two“activitiesbequalifiedpartymembersbothastartingpointendin

20、gpoint.PartycadresonlyopinionsFoundationConstitutionPartyrulesseriestobetteraddressoutsideinshape“two“thisisStateleadingbyexampletoleadbyexampletobequalifiedpartymembersintheprocessofdoingthedeepsolidhighermestringent.Jo

21、bswithnewskills.Tobeaqualifiedpartymembermostbasicelementisalwaysadvancedrequirementsthemselvesusingtheirpowertopushfwardthecauseofthepartythepeoplethenation.Istotheleadingcadresofpartymembersfirstofallisbasedonthejobdot

22、hepeopleintheheart.Thereisnotasloganbutaimstobetterservethepeopletargetedefftstoincreasethecapacity第四章第四章隨機變量的數(shù)字特征隨機變量的數(shù)字特征1.甲、乙兩臺自動車床，生產(chǎn)同一種零件，生產(chǎn)1000件產(chǎn)品所出的次品數(shù)分別用?，?表示，經(jīng)過一段時間的考察，知?，?的分布律如下：?0123?012p0.70.10.10.1p0.50.30.2

23、試比較兩臺車床的優(yōu)劣。解：因為E?=0?0.71?0.12?0.13?0.1=0.6E?=0?0.51?0.32?0.2=0.7。故就平均來說，甲機床要優(yōu)于乙機床。2.連續(xù)型隨機變量?的概率密度為fxkxxkaa()()???????0100其它又知E?=0.75，求ka之值。解：首先由密度函數(shù)性質(zhì)知1111)(???????????????akdxkxdxxfa即；又E?=0.75，即有75.02175.0)(1???????????

24、?????akdxkxdxxxfa即；由上述兩式可求得k=3a=2。3.已知隨機變量?的分布律為?1023p18143814求E?，E(3?2)，E?2，E(1?)2。解：E?=(1)?(18)0?(14)2?(38)3?(14)=118E?2=(1)2?(18)02?(14)22?(38)32?(14)=318E(1?)2=(1(1))2?(18)(10)2?(14)(12)2?(38)(13)2?(14)=178或者，E(1?)2=

25、E(12??2)=1(E2?)E?2=178。4.若?的概率密度為fxex()||??12。求(1)E?，(2)E?2。解：(1)dxxeEx??????||21?中因e|x|為偶函數(shù)，x為奇函數(shù)，故xe|x|為奇函數(shù)，且積分區(qū)間關(guān)于原點對稱，該積分又絕對收斂，事實上?????????????????????1)2(||21)(||0||dxxedxexdxxfxxx故E?=0。(2)dxxfxE)(22??????2!2)3(2102

26、||2???????????????dxexdxexxx。5.輪船橫向搖擺的隨機振幅?的概率密度為fxAxexxx()()??????????2220000??求(1)確定系數(shù)A；(2)遇到大于其振幅均值的概率是多少？解：(1)由密度函數(shù)性質(zhì)知22111)(22?????????????????AdxAxedxxfx即leadingcadresawarenessofrightinplacestudythepartyConstitutio

27、npartyrulesseriesofspeechescanmakepropereffect.Partycadresto“two“l(fā)eadbyexampletoleadbyexamplewemustchangeourmindrecognizingthat“two“isimptant.FirstlearntheCommunistPartyConstitutionPartyruleslearninglearningseriesimptant

28、speechbyGeneralSecretarycanenhancethey.Withthe“thirdrevolution“theriseofrapidchangesinourlifearefeelingtheCommunistsshouldadheretothetheyofconfidencewillcontinuetolearnfromthevoicesofthetimesthetimesinturnwillhavenewrequ

29、irementsfleadingpartycadres.“Two“isthemostbasicmeaningofmembersallmasteringthecetheythemostadvancedweaponstheycomplementthespiritofcalcium.SecondlytheCommunistPartyConstitutionPartyruleslearninglearningseriesimptantspeec

30、hbyGeneralSecretarybeabletofirmlybuildtheideologicalfoundation.Undertheimpactofmultiplevaluesthe“two“istohelpcultivateindependentjudgmentinnumerousmiscellaneousmultipleconceptssothatthemajityconsensusofpartymemberstheimp

31、tantmagicweaponofthepartywiththeresonancefrequency.FinallytheConstitutionoftheCommunistPartypartyruleslearninglearningseriesimptantspeechcanstcrowdsGeneralSecretaryposition.Nowsomegrassrootswkinthe“theoldwaydidntwkhardwa

32、ycannotthenewapproachwouldnot“phenomenonsometimesduetoamassofpartymemberscadresnotunderstingdoesnotmeet.Infactthemass“convincing““identity“Behindarelikelytobepartymembersleadingcadresthemselvesigningbeliefsheldresultingi

33、nlackofpersuasionsenseofidentity.“Two“isinfactguaranteedpartycadreswkanimptantprerequisitefconvincingthemasses.Baconsaiditwell:“practicalmencanhleindividualmattersbutlookingatthewholeoperationgloballybutonlymancandotokno

34、wledge.“Givingup“two“effectivemustfirstraiseawarenessofleadingcadresofpartymembersaspartymemberslearnrealresponsibility“toknow“to“music““good“changesinparallelwiththegrounddonotfgettoalsoanswertheantennadrawcatchesonmete

35、ologywhichsitbetweenheavenEarthwhichmeldstogetherthedreamsofpracticingCommunist.Memberscadresshouldin“twolearnado“inthebasedpostdocontributioninallmembersinthecarriedout“l(fā)earnConstitutionPartyruleslearnseriesspeechdoqual

36、ifiedmembers“l(fā)earningeducationthisisfollowingpartyofmasslineeducationpracticeactivities“threestrictthreereal“topiceducationzhihoudeepeningpartyeducationofonceimptantpracticeispromoted“threestrictthreereal“topiceducationf

37、rom“keyminity“toallmembersexpfromconcentratededucationtoregulareducationextendsofimptantinitiatives.Vastnumbersofpartymemberscadresinthecourseoftwoshouldbebasedontheiractualstrivingtobe“l(fā)earning““done“markers.Strengtheni

38、ngtheeticalstudybelieffaith.Theyisanactionguideonlytheeticalknowledgeinplacetounityactioncanconsciously.ConstitutionisthefundamentallawofthepartypartyrulesarepartymustfollowtheGeneralrules.StudyingimplementingthepartyCon

39、stitutionPartyrulesaseriesofimptantspeechGeneralSecretaryisaguidetopersistingdevelopingsocialismwithChineseacteristicsisabasicwkofstrengtheningthepartysconstructionbutalsoeacheveryCommunistPartyMembersobligationssolemnre

40、sponsibility.Theseimptantcontentfeachpartymustknowwouldbelievewilldoboth.WeGeneralSecretaryofthepartyConstitutionaseriesofremarkswithholdgraspthereal“l(fā)earning“thatbasisbasedontheConstitutionspeaktoissueinaccdancewiththes

41、erieschangedtheproblem.Seconddisciplinedinlinetobecomelawabidingmodel.Isnotnorules.Ifthereisnoirondisciplinepartymemberscadreswillbecomeamessitwillloseitsfightingstrengthvitalitypuritynaturallymuchlessadvanced.By“two“edu

42、cationpartymemberscadrestokeepthe“bottomline“nottheme“redlines“consciouslypracticethe“threeSuns“consciouslyactaccdingtotheConstitutionpartyrulesremainsapoliticalfcetoperfmpartyoathatreeofitsownimage.Threeistheloyaldareto

43、playplaytopartymembers.LearningistheFoundationisthekeytodevelopmentisthegoal.“Two“mainobjectiveistoletthemajityoftheplaytotheexemplaryroleofpartymemberscadrespartyConstitutionpartyrulestoexamine.Tousenewcriteriatoguideou

44、rbehavi.Througheducationtheidealconvictionkeepinmindthatmembershiplearnlearnlearngoplayavanguardexemplaryrolethecouragetoplayasalwaysmaintainthepioneerpioneeringenterprisingspiritconstantlyimproveourowncapacitylevelofser

45、viceaccdingtopositionsmakecontributions.Heartschangeleadmestrict“beganintheknowknowasLukeSkywalker““two“activitiesbequalifiedpartymembersbothastartingpointendingpoint.PartycadresonlyopinionsFoundationConstitutionPartyrul

46、esseriestobetteraddressoutsideinshape“two“thisisStateleadingbyexampletoleadbyexampletobequalifiedpartymembersintheprocessofdoingthedeepsolidhighermestringent.Jobswithnewskills.Tobeaqualifiedpartymembermostbasicelementisa

47、lwaysadvancedrequirementsthemselvesusingtheirpowertopushfwardthecauseofthepartythepeoplethenation.Istotheleadingcadresofpartymembersfirstofallisbasedonthejobdothepeopleintheheart.Thereisnotasloganbutaimstobetterservethep

48、eopletargetedefftstoincreasethecapacityEL=E(??)=?E?=2)(ba??，DL=D(??)=?2D?=12)(22ab??；EA=??24=??????bababadxabxE)(121442222????，又4?E=???????babbaabbaadxabx)(5114322344，因此DA=EA2(EA)2=2222422222)(14416)](12[)4(babaEbabaE???

49、??????????=22224322342)(144)(5116bababbaabbaa??????????)474()(7202222babaab?????10.設隨機變量?，?相互獨立，其概率密度分別為：fxxxxx?()???????????012120其它，fyeyy?()??????00其它試求E(??)，D(??)。解：因為????????????211021)2()(dxxxdxxdxxxfE??，???????????

50、?2121032267)2()(dxxxdxxdxxfxE??，????????????01)(dyyedxyyfEy??，????????????02222)(dyeydxyfyEy??，又?與?是獨立的，故有E(??)=E??E?=1?1=1；D(??)=D?D?=6712167])([])([2222????????????EEEE。11.設隨機變量?與?相互獨立，且E?=E?=0，D?=D?=1，求E(??)2。解：E(??)2

51、=E(?22???2)=E?22E(??)E?2，又?與?相互獨立，因此E(??)=E??E?，而D?=2222)()(?????EDEEE????，同理22)(???EDE??故有E(??)2=E(?22???2)=E?22E??E?E?2=2)(??ED?2E??E?2)(??ED?=11=2。12.若連續(xù)型隨機變量的概率密度是fxaxbxcx()????????2010其它且已知E?=0.5，D?=0.15，求系數(shù)abc。解：因為