The GATE Grind

GATE Estimation: Point Estimation and Consistency – Previous Year Questions

16 GATE previous year questions on Point Estimation and Consistency (Estimation, Statistics) with answers and explanations, from every paper.

  1. GATE 2021 ST Q13 (1 mark, Multiple choice) – An iid sample of size n≥2 has density exp[−(x−θ)/θ]/θ for x>θ,zero otherwise,θ>0. Find the method-of-moments estimator of θ.
  2. GATE 2021 ST Q61 (2 marks, Numerical answer) – The observations .90,.50,.01,.95 are iid with density [θ/(1−θ)]x[(2θ−1)/(1−θ)] on 0<x<1,where .5≤θ<1. Find the MLE of θ,to two decimals.
  3. GATE 2022 ST Q13 (1 mark, Multiple choice) – S² is the sample variance with divisor n−1 from n>1 iid normal observations with unknown μ and σ²>0. I:S² is unbiased for σ² and S is unbiased for σ.…
  4. GATE 2022 ST Q33 (1 mark, Numerical answer) – Four observations 6,5,3,6 come from density 2(θ−x)/θ² on 0<x<θ,zero elsewhere. Find the method-of-moments estimate of θ as an integer.
  5. GATE 2022 ST Q58 (2 marks, Numerical answer) – An iid size-five sample from density 3x²/θ³ on 0<x<θ is 3,6,4,7,5. Find the MLE of the 1/8 quantile,to one decimal.
  6. GATE 2023 ST Q22 (1 mark, Multiple choice) – X has exponential density e(−x/λ)/λ for x>0,λ>0 unknown. Y₁,…,Y n are iid with the distribution of X² and Ȳ is their mean. Which is the…
  7. GATE 2023 ST Q23 (1 mark, Multiple choice) – An iid sample of size n≥2 has density f(x;θ)=2(−ln x) exp[−(ln x)²/θ]/(θx) on 0<x<1,zero otherwise,θ>0. Which expression is the MLE of θ?
  8. GATE 2023 ST Q39 (2 marks, Multiple choice) – An iid sample of size n has density exp[−(x−μ)] for x≥μ,zero otherwise,μ unknown. Let M̂ be the MLE of the population median. Which holds when μ=1?
  9. GATE 2023 ST Q40 (2 marks, Multiple choice) – X₁,…,X₁₀ are iid N(0,θ²),θ>0. Set T=ΣX i²/10. For c>0,the MSE of cT as an estimator of θ² is minimized at c₀. Find c₀.
  10. GATE 2024 ST Q24 (1 mark, Multiple choice) – An iid sample n≥2 has density θ(2x)(θ−1) on 0<x≤1/2 and θ(2−2x)(θ−1) on 1/2<x≤1,zero otherwise,θ>0. Put L=Σ (X i≤1/2)ln(2X i)+Σ (X i>1/2)ln(2−2X i),…
  11. GATE 2024 ST Q44 (2 marks, Multiple choice) – Independent X n~Poisson(λ+2(−n)),λ>0 unknown. Which holds?
  12. GATE 2024 ST Q62 (2 marks, Numerical answer) – A Poisson process N(t) of unknown rate λ counts road potholes up to distance t km. Starting at zero, potholes occur at distances…
  13. GATE 2025 ST Q32 (1 mark, Numerical answer) – Observed Bernoulli sample values are 0,1,1,1,0, with parameter θ∈(0,.7]. Find the MLE of θ to two decimals.
  14. GATE 2025 ST Q61 (2 marks, Numerical answer) – Seven iid observations have density (λ³x²/2)e(−λx),x>0,λ>0 unknown. The MLE λ̂ has bias E(λ̂−λ)=αλ. Find 1/α (integer).
  15. GATE 2026 ST Q32 (1 mark, Numerical answer) – A gamma sample has density λαx(α−1)e(−λx)/Γ(α),x>0, with unknown α,λ>0. The observed averages of x i and x i² are 2 and 5. Find the method-of-moments…
  16. GATE 2026 ST Q56 (2 marks, Multiple select) – An iid sample n≥2 has Laplace density e(− x−μ )/2,μ∈ℝ. Let μ̂ be an MLE and X̄ the sample mean. Which hold?