数理统计第四章习题答案1解:母体子样子样平均1X11X,12X,…,11nX1X2X21X,22X,…,22nX2X……rX1rX,2rX,…,rrnXrX11111122112221111()()1()()11011()()111()()iiiinniijijijjiinnrrijijijijiirrAiiiiiirriiiiiiybxcbxbcbXcnnbybxcxbcbXcnnXcyXcybbbSnXXncycybbnyynyybbb令221()rAiiAiSnyybS2222211112222111111111()()11()()rrrrAAAAAAnnrrEijiijiijijnnrrijiijiijijSbSSbSrrSSbSxXcycybbyyyybb令2211()rnrEijiEijSyybS22222111EEEEEEAAAEEESbSSbSnrnrSSbSSSbFFSSSb2解:假设01234:H11234:H不全为零生产厂干电池寿命iXA24.7,24.3,21.6,19.3,20.322.04B30.8,19.0,18.8,29.724.575C17.9,30.4,34.9,34.1,15.926.64D23.1,33.023.026.418.125.124.7831234454562024.52rnnnnnX经计算可得下列反差分析表:来源离差平方和自由度均方离差组间53.6511317.8837组内603.01981637.6887总和656.670919查表得0.05(3,16)3.24F0.0517.88370.4745(3,16)37.6887FF故接受0H即可认为四个干电池寿命无显著差异。3解:假设0123:H1123:H不全相等小学身高数据(厘米)iX第一小学128.1,134.1,133.1,138.9,140.8,127.4133.733第二小学150.3,147.9,136.8,126.0,150.7,155.8144.583第三小学140.6,143.1,144.5,143.7,148.5,146.4144.46712336140.9278rnnnX经计算可得下列方差分析表:来源离差平方和自由度均方离差F值组间465.8862232.9434.372组内799.251553.385总和7265.136170.050.05(2,15)3.684.3733.68(2,15)FFF拒绝0H故可认为该地区三所小学五年级男生平均身高有显著差异。4解:假设01234:H11234:H不全相等伏特计测定值iXA100.9,101.1,100.8,100.9,100.4100.82B100.2,100.9,101.0,100.6,100.3100.6C100.8,100.7,100.7,100.4,100.0100.52D100.4,100.1,100.3,1060.2,100.0100.2123445100.535rnnnnX经计算可得下列方差分析表:来源离差平方和自由度均方离差F值组间0.989530.32984.0716组内1.296160.081总和2.2855190.05(3,16)3.24F0.05(3,16)3.24FF拒绝0H故可认为这几支伏特计之间有显著差异。5解:假设012345:H112345:H不全相等温度(C)得率(%)iX60909288906597939294709696939575848388858084868284123455389.6rnnnnnX经计算可得下列方差分析表:来源离差平方和自由度均方离差F值组间303.6475.915.18组内50105总和353.6140.050.05(4,10)3.4815.18(4,10)FFF拒绝0H故可认为温度对得率有显著影响215151511(,())XXNnn由T检验法知:151515()()11EXXTtnrSnn给定的置信概率为10.950.025{()}0.95PTtnr故15的置信概率为0.95的置信区间为150.025150.02515151111((),())EEXXtnrSXXtnrSnnnn52.236EEQSnr0.025(10)2.2281t由上面的数据代入计算可得:150.025150.02522(10)90842.22812.2361.9322332(10)10.06783EEXXtSXXtS故15的置信区间为(1.9322,10.0678)234343411(,())XXNnn由T检验法知:343434()()11EXXTtnrSnn34的置信区间为:340.025340.02534341111((),())EEXXtnrSXXtnrSnnnn代入数据计算得:340.02534340.02534112(10)102.22812.2365.9327311(10)14.0678EEXXtSnnXXtSnn故34的置信区间为(5.9322,14.0678)6解:2(,)iiiiXNEX又矩估计法知11iniiijjiXxn11111inrriiijiijiiinxXnnXX且1111112222111111()()(0)()[()()]11()2[()()][()]iiiiiinnnnrriiijijiijijjijiiiiiiiiinniiiiiiiiiijjEEXEXExExnnnnDEXXEXXEXEXnXEnXnn注意到2[()()]()()0((,))iijjiijjiiiEXXEXEXXNn22222122121()()()21riiiiiiiiiriiiiiiEXnEXnEXnnDXnDXnDXnn上式2222221222221()2111()riiiiiiiiiinnDXnnnnnnnnnnn7解:因子B因子A1B2BsB.iX1A11X12X1sX1.X2A21X22X2sX2.XrA1rX2rXrsX.rX.jX.1X.2X.sXX....22..112.2111111()()1()iijjrrAiiiiriiXcyXcybbXcybSsXXscycybbsyyb令22.1()rAiAiSsyybS,则2AASbS22..112.2111()()1()ssBjjjjrjjSrXXrcycybbryyb令22.1()sBjBjSryybS,则2BBSbS22....11112..211111()()1()rsrsEijijijijijijrsijijijSxXXXcycycycybbbyyyyb令2..11()rsEijijijSyyyy则2EESbS,2EESbS22AAAAAEEESbSSFFSbSS22BBBBBEEESbSSFFSbSS8解:假设01123:0H假设021234:0H加压机器iX1B2B3B4B1677.751A15771692180016421644.752A15351640178316211679.253A15921652181016631667.253r,4s来源离差平方和自由度均方离差F值因子A304221521AF=6.3436因子B82597.64327532.547BF=114.8298误差1438.616239.7683总和87078.25110.01(2,6)10.92F0.01(3,6)9.78F0.01(2,6)AFF0.01(3,6)BFF故接受01H,拒绝02H即可认为不同加压水平对纱支强度无显著差异;既可认为不同机器对纱支强度有显著差异。9解:假设011234:0H假设02123:0H假设03:01,2,3,4;1,2,3ijHij机器操作工..iX甲乙丙1A15,15,1719,19,1616,18,2117.3(15.67)(18)(18.33)2A17,17,1715,15,1519,22,2217.67(17)(15)(21)3A15,17,1618,17,1618,18,1817(16)(17)(18)4A18,20,2215,16,1717,17,1717.67(20)(16)(17)..jX17.16716.518.58317.417433,ABrskFF和IF的值可按入夏二元方差分析表来引进来源离差平方和自由度均方离差F值机器A2.838630.9462AF=0.5488BF=7.8756IF=7.093机器B27.155213.5775交互作用73.3698612.2283误差42.3866241.724总和144.75350.05(3,24)3.01F0.05(2,24)3.40F0.05(6,24)2.51F0.05(3,24)AFF0.05(2,24)BFF0.05(6,24)IFF故接受01H,拒绝02H,03H即可认为机器之间的差异不显著,操作工之间的差异显著,交互作用的影响也显著。10、解:假设01123:0H021234:0H03:01,2,3,;1,2,3,4ijHij浓度(%)温度(C)..iX10243852214,1011,1113,910,1211.25(12)(11)(11)(11)49,710,87,116,108.5(8)(9)(9)(8)65,1113,1412,1314,1011.5(8)(13.5)(12.5)(12)..jX9.311.1710.8310.310.417342,ABrskFF和IF的值可按入夏二元方差分析表来源离差平方和自由度均方离差F值浓度A44.3222.176AF=4.092BF=0.7114IF=0.829温度B11.560233.8534交互作用26.94364.4905误差64.9998125.4167总和147.833230.05(2,12)3.89F0.05(3,12)3.49F0.05(6,12)3.00F0.05(2,12)AFF0.05(3,12)BFF0.05(6,12)IFF故拒绝01H,接受02H,03H即可认为浓度对得率的影响显著,而温度和交互作用对得率的影响不显著。11、解:由题意:设温度为因子A,加碱量为因子B,催化剂种类为因子C假设01123:0Haaa0212303123:0:0HbbbHccc则可列下表:列号试验号ABC试验值平方111151260121227150413133583364422826724522369476162315934817313775929832185722593328470561k180210195k=636,w=461822k2102252373k246201204u