LOYOLA COLLEGE (AUTONOMOUS), CHENNAI – 600 034
M.Sc. DEGREE EXAMINATION – STATISTICS
SECOND SEMESTER – APRIL 2011
ST 2811 / 2808 – ESTIMATION THEORY
Date : 2/4/2011 Dept. No. Max. : 100 Marks
Time : 1:00 – 4:00
SECTION – A
Answer all the questions (2×10=20)
- Define Minimal Sufficient Statistic
- Define Efficient Estimator
- Define Ancillary Statistic
- State the different approaches to identify UMVUE
- Define Likelihood Equivalence
- Define D –optimality
- Define Location-Scale Family
- Define Minimum Risk Equivariant Estimator(MREE)
- Define CAN estimator
- Define Maximum Likelihood Estimator
SECTION – B
Answer any five questions (5×8 = 40)
- Obtain UMVUE of θ(1- θ) using a random sample of size n drawn from a Bernoullie population with parameter θ
- State and Establish Rao-Blackwell theorem
- State and Establish Neyman-Fisher Factorization theorem
- i) Let L be squared error then MREE of θ is unique (4)
- ii) Let X1,X2,…,Xn be a random sample from N(θ,1), Show that (4)
- Let δ be a LEE and L be invariant then show that i)The Bias of δ is free from θ
and ii) Risk of δ is free from θ (4+4)
- i) State and Establish Basu’s theorem (6+2)
- ii) Define UMRUE
- Determine MREE of θ in the following cases i) N(θ,1) , θ Î R ii)E(θ,1) , θ ÎR
- Let X1,X2,…,Xn be a random sample from population having pdf
obtain MLE of P(X>2)
SECTION – C
Answer any two questions (2×20 = 40)
- i) Establish: If UMVUE exists for a parametric function Ψ(θ), It has to be essentially unique (10)
- ii) State and Establish Cramer-Rao Inequality for multi-parameter case and hence deduce the inequality for single parameter (10)
- Establish: δ*Î Ug is D-optimal if and only if each component of δ* is UMVUE
- i) Let X1,X2,…,Xn be a random sample from N(µ,σ2). Obtain Cramer-Rao lower bound for estimating (16)
- i) µ ii) σ2 iii) µ+σ iv) σ/ µ
- ii) Establish: Let T be a sufficient statistic such that T(x) = T(y) then (4)
- i) Establish: Let δ* belong to the class of LEEs. Then δ* is a MREE with respect to squared error if and
only if E(δ*u)=0 (10)
- ii) Let X1,X2,…,Xn be a random sample drawn from a normal population with mean θ and variance σ2
Find the MLE of θ and σ2 when both θ and σ2 are unknown (10)