LOYOLA COLLEGE (AUTONOMOUS), CHENNAI – 600 034
M.Sc. DEGREE EXAMINATION – STATISTICS
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SECOND SEMESTER – APRIL 2007
ST 2808/2806/2801 – ESTIMATION THEORY
Date & Time: 17/04/2007 / 1:00 – 4:00 Dept. No. Max. : 100 Marks
SECTION – A
Answer all the questions (10 x 2 = 20)
- Explain the problem of Point estimation.
- Give two examples of loss function for simultaneous estimation.
- If δ is a UMVUE, then show that δ + 2 is also a UMVUE.
- Define Fisher information in the multi-parameter case.
- Define minimal sufficient statistic.
- Give an example of a family of distributions which is not complete.
- Give two examples of scale equivariant estimator.
- Let X follow B(1, θ), θ = 0.1,0.2. Find MLE of θ .
- Given a random sample from DU{1,2,…, N}, N ε I+, find a consistent estimator of N.
- Explain Bayes estimation.
SECTION – B
Answer any five questions (5 x 8 = 40)
- If δ0 is an unbiased estimator of g, show that the class of unbiased estimators of g is
{ δ0 + u │u ε U0}.
- Given a random sample from N(μ, σ2), μ ε R , σ > 0, find Cramer-Rao lower bound for
estimating σ/ μ.
- State and establish Bhattacharya inequality.
- Let X1,X2,…,Xn be a random sample from U(θ – 1, θ + 1), θ ε R. Show that
(X(1), X(n)) is minimal sufficient but not complete.
- State and establish Basu’s theorem.
- Given a random sample from E(ξ,1), ξ ε R, find MREE of ξ with respect to i) squared error loss and
- ii) absolute error loss.
- State and prove the theorem providing MREE of a scale parameter.
- Given a random sample from U(0, θ), θ ε R, show that MLE is not CAN. Suggest a CAN estimator.
SECTION – C
Answer any two questions (2 x 20 = 40)
19 a) State and establish Cramer-Rao inequality for the multiparameter case.
- b) Let X follow DU{1,2,…,N}, N = 3,4,… Find the UMVUE of g(N). Hence find the UMVUE of N.
20 a) Show that an estimator is QA – optimal if and only if it is D – optimal.
- b) Given a random sample from E(ξ, τ), ξ ε R, τ > 0, find UMRUE of (ξ , ξ + τ) with
respect to any loss function, convex in the second argument.
21 a) Discuss the problem of equivariant estimation of the percentiles of a location – scale model.
- b) Given a random sample of size n from N(μ, τ2), μ ε R, τ > 0, find MREE of (μ+3τ) with respect to
standardized squared error loss.
22 a) State and establish invariance property of CAN estimator.
- b) Let (Xi,Yi) , i= 1,2,…,n be a random sample from a bivariate distribution with pdf
Find MLE of
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