若跑一个最小平方法,得到下列数据: ^ 5 ^ ^ 3 1 1 β=[-4 ] and Σ= σ^2(X'X)^(-1)=[ 1 2 1 ] 2 1 2 3 a.On the basis of this information, how would you estimate β, if you believed that β_1+β_2=β_3 and β_2+β_3=0? b.What rationale would you give for your estimator? 这是今年清大经研的统计 我知道那些矩阵代表的意思 可是a.b.小题我完全不知道它想问什麽 麻烦了解的人救救我~感谢~~~ 另外还有两个小问题 1.若以无母数的方法作卡方齐一性检定,需要什麽重要的假设? 印象中没听过需要什麽假设,也麻烦知道的人赐教~ 2.In a certain community, 8% of all adult over 50 have diabetes. If a health service in this community correctly diagnoses 95% of all persons with diabetes as having the disease and incorrectly diagnoses 2% of all persons without diabetes as having the disease, find the probabilities that a.the community health service will diagnose an adult over 50 as having diabetes. b.a person over 50 dianosed by the health service as having diabetes actually has the disease. 这一题一下子adult一下子又person,搞的我糊里糊涂 我的作法是a.0.08*0.95+0.92*0.02 b.(0.08*0.95)/(0.08*0.95+0.92*0.02) 不知道有没有错误~感谢~~~^^ --

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