生物统计学(a)2009答案解析

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1、专业：学号：姓名：装订线南京师范大学生命科学学院2008-2009学年第一学期硕士研究生期末考试《生物统计学》试卷（A）题号一二三四五六总分得分得分一、简答题（每小题4分，共20分）1、最常见的数据类型（Themostcommontypesofdata）答：Quantitativedata,ranked(ordinal)data,andcategorical(nominal)data2、为何需要数据转化（Whydatatransformation）答：threeassumptionsforparametricanalyses(1)Datafromeachgroupwereobtainedran

2、domlyfromanormalpopulation;(2)thesampledpopulationsmustallhaveequalvariances(inwhichcaseitcanbesaidthatthevariancesarehomoscedastic);and(3)theeffectsofthefactorlevelsmustbeassumedtobeadditiveDataneedtobetransformediftheaforementionedthreeassumptionsarenotmetwhenemployingparametricandotherrelatedanal

3、yses3、如何从总体抽样（Howtosamplefrompopulations）答：Randomlysampling-randomtableandotherrandomlysamplingmethodsSizeandshapeofsamplesSizeandnumberofsamples-whenprecisionisholdconstant,thereisaninverserelationshipbetweensizeandnumberofsamplesN=4s2/d24、双因子方差分析的变异来源（Sourcesofvariationintwo-factoranalysisofvarian

4、ce）答：within(error)groups(samples)SS=S[S(Xij–Xi)2],withingroupsDF=S(ni–1)=N-kamonggroupsSS=Sni(Xi–X)2]=S[(SXij)2/ni]–CamonggroupDF=k–1totalSS=SS(Xij–X)2=errorSS+groupsSS=SSXij2–CtotalDF=N–1=errorDF+groupsDFC=(SSXij)2/N5、试述统计分析的重要性（Whystatisticalanalysesimportant）答：Manyoftheinvestigationsinlifescience

5、shavebecomequantitative,inthatagreatmanytypesofenvironmentalobservationsconsistofnumericalfactscalleddata.Aslifeentitiesarecountedormeasured,itbecomesapparentthatsomeobjectivemethodsarenecessarytoaidtheinvestigatorincollecting,presenting,analyzingandreportingresearchdata.Beforedatacanbeanalyzed,they

6、mustbecollected,andherestatisticalconsiderationscanaidinthedesignofexperimentsandinthesettingupofhypothesestobetested.Thus,aknowledgeofbasicstatisticalprinciplesandproceduresisimportantevenbeforeanexperimentisbegun.得分二、基础统计分析（1-2每小题5分，3-5每小题10分，共40分）1、用下表人类头发颜色观测频次（O）的抽样数据，要求：（1）填写头发颜色的理论频次分布；（2）用卡方

7、好适度检测和对数似然比例检测人类黑色、棕色、金色和红色头发颜色是否吻合2：2：2：1的颜色分布。显著性水平为0.05、自由度为3条件下的X2临界值是7.815[Thefollowingdataarerecordedastheobservedfrequencies(O),bywhichyoumayusetotestwhetherthesamplecomesfromapopulationhavinga