精華區beta NTU-Exam 關於我們 聯絡資訊
課程名稱︰高等統計推論二 課程性質︰選修 課程教師︰鄭明燕 開課學院:理學院 開課系所︰數學系 考試日期(年月日)︰102.06.19 考試時限(分鐘): 是否需發放獎勵金:是 (如未明確表示,則不予發放) 試題 : Advanced Statistical Inference II Final Examination 19 Jun 2014 1. Let X=(X1,X2,....Xn), where X1,X2,....Xn are iid random variables from a Bernouli(p) distribution. Consider testing:H0:p=p0 versus p≠p0. (a)10% Derive an expression for -2logλ(x), where λ(x) is the LRT statistic. (b)10% Give an approximate level α test. 2. A random sample of X1,....,Xn is drawn from a Gamma(α,β) population with pdf 1 f(x│α,β)= -------------x^(α-1)e^(-x/β)I (x),α>0,β>0. Gamma(α)β^α (0,∞) where α is known, β is unknown and I is the indicator function. Consider testing: H0:β=β0 versus β≠β0. (a)10% Derive a Wald statistic and a score statistic. (b)10% Construct approximate level α tests using the test statistic in (a). 3. (10%) Verify that g(y)=y^0.5 is a variance stabilizing transformation of a Poisson random variable. 4. Assume the one-way ANOVA null hypothesis is true. ─ k (Yi- Y)^2 (a)10% Show thatΣ --------------- gives an unbiased estimator of σ^2. i=1 k-1 (b)10% Derive the ANOVA F test. 5. Suppose the random variables Y1,Y2,....Yn satisfy Yi=βxi + ei, i=1,....,n where x1,x2,....xn are fixed constants,e1,e2,....en are iid Normal(0,σ^2) errors, and β and σ^2 are unknown constants. (a)10% Find the MLEs of β and σ. (b)10% Show that ΣYi/Σxi and n^(-1)Σ(Yi/xi) are both unbiased estimators of β. (c)10% Compare the variances of the estimators of β in (a) and (b). -- ※ 發信站: 批踢踢實業坊(ptt.cc), 來自: 111.243.102.90 ※ 文章網址: http://www.ptt.cc/bbs/NTU-Exam/M.1405102596.A.A3C.html ※ 編輯: d3osef (111.243.102.90), 07/12/2014 03:15:52