The GATE Grind

GATE 2021 ST – Question 50

Estimation · Sufficiency and Completeness · 2 marks · Multiple choice

For an iid size-n sample from Uniform(0,θ),θ>0,n≥2,let X_(1),X_(n) be the extremes. P:(X_(1),X_(n)) is complete. Q:the range X_(n)−X_(1) is ancillary. Which hold?

  1. P only
  2. Q only
  3. Both P and Q
  4. Neither P nor Q

Practise this question in The GATE Grind →

Show answer and explanation

Correct answer: (D) Neither P nor Q

Explanation

The nonzero function g=min−max/n has expectation θ/(n+1)−[nθ/(n+1)]/n=0 for every θ,so the pair is not complete. The range scales with θ and its mean is (n−1)θ/(n+1),so its law depends on θ and it is not ancillary. Neither holds. **D**.

More Sufficiency and Completeness questions

All Sufficiency and Completeness questions →