數(shù)學難題

1、1.ABCDE五個人的薪水的median是20000range不超過50000其中ABC的薪水分別是200004000050000問五個人薪水的平均值可能是多少(A)20000(B)32000(C)18000(D)23000(E)310002.一個樣本在一個標準方差內(nèi)的概率是0.68兩個標準方差內(nèi)的概率是0.95.一樣本mean=18.6標準方差是6求:該樣本在6.612.6內(nèi)占多少(A)0(B)0.68(C)0.27(D)0.36(E

2、)0.1353.一組數(shù)平均值9標準方差2另外一組數(shù)平均值3標準方差1問第一組數(shù)在(511)中的數(shù)占總數(shù)的比例和第二組數(shù)在(14)中的數(shù)占總數(shù)的比例哪個大4.有100個人都對AB兩個人進行評價每個人只有兩種選擇即好或不好說A不好的有59個說B不好的有65個問:同時說AB都好的人數(shù)和35比較哪個大5.兩個集合:A=[1234]B=[2345]問B的A次方有多大的概率是正數(shù)(A)0(B)0.5(C)0.625(D)0.875(E)0.1356

3、.符合X^2Y^2=100的整數(shù)解共有多少對7.RighttrianglePQRistobeconstructedinthexyplanesothattherightangleisatPPRisparralleltothexaxis.ThexycodinatesofPQRaretobeintegersthatsatisfytheinequalities4=x=56=y=16howmanydifferenttriangleswiththe

4、sepropertiescouldbeconstructed(A)110(B)1100(C)9900(D)10000(E)121008.Aboxcontains100ballsnumberedfrom1to100.Ifthreeballsareedatromwithreplacementfromtheboxwhatistheprobabilitythatthe14.TheprobabilityofAis60%theprobability

5、ofBis50%whatisthemostpossibleprobabilitythatneitherAnBwouldhappen(A)0.80(B)0.40(C)0.75(D)0.55(E)0.6815.Inaninsurancecompanyeachpolicyhasapaperrecdanelectricrecd.Fthosepolicieshavingincrectpaperrecd60%alsohavingincrectele

6、ctricrecdFpolicieshavingincrectelectricrecd75%alsohavingincrectpaperrecd.3%ofallpolicieshavebothincrectpaperincrectelectricrecds.Ifweromlypickoutonepolicywhatstheprobabilitythattheonehavingbothcrectpapercrectelectricrecd

7、s(A)0.80(B)0.94(C)0.75(D)0.88(E)0.9216.Thereare1200respondentstoapolleachfavingtheirpreferencefcidatesABC.54%favedA48%favedB42%favedCthereis30%favedbothAB.whatsthelargestpossiblenumberofrespondentsfavingCbutnotC&BnC&A(A)