# PracticeQuestions6Answers - 2 2 2 1 2 4 4 2 Var X Var X Var...

This preview shows pages 1–2. Sign up to view the full content.

Practice Questions 6 1. C 2. B 3. D 4. C 5. B 6. B 7. D 8. C 9. B 10. A 11. D 12. B 13. C 14. C 15. A 16. A 17. D 18. B 19. B 20. C 21. D 22. 1 / 2 , / n X t s n α - = 63.57 = 2.032(17.32) / 5.92 = 63.57 = 35 = 63.57= 5.95. Then, UCL = 69.52 and LCL = 57.62. 23. If independent random samples of size 35 are repeatedly selected from the population and 95% confidence intervals for each of these samples are determined, then over a very large number of repeated trials, 95% of these intervals will contain the value of the true average amount of money a typical college student spends per day during spring break. 24. 1 2 ( ) [ ( ) ( )]/ 2 ( ) / 2 E X E X E X μ = + = + = 1 2 ( ) [ ( ) 3 ( )]/ 4 ( 3 ) / 4 E Y E X E X = + = + = 1 2 ( ) [ ( ) 2 ( )]/ 3 ( 2 ) / 3 E Z E X E X = + = + = Since ( ) ( ) ( ) E X E Y E Z = = = , then all three estimators are unbiased. 25.

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: 2 2 2 1 2 ( ) [ ( ) ( )]/ 4 ( ) / 4 / 2 Var X Var X Var X σ = + = + = 2 2 2 1 2 ( ) [ ( ) 9 ( )]/16 ( 9 ) /16 5 /8 Var Y Var X Var X = + = + = 2 2 2 1 2 ( ) [ ( ) 4 ( ) / 9 ( 4 ) / 9 5 / 9 Var Z Var X Var X = + = + = Hence, X is the most efficient estimator since ( ) ( ) ( ) Var X Var Z Var Y < < . Note that 1 2 ( )/ 2 X X X X = + = , then, 2 2 ( ) ( ) / / 2 Var X Var X n σ = = = . 26. Relative efficiency of X with respect to Y = ( ) / ( ) Var Y Var X = (5 2 / 8) / ( 2 / 2) = 5 / 4 = 1.25 Relative efficiency of X with respect to Z = ( ) / ( ) Var Z Var X = (5 2 / 9) / ( 2 / 2) =10 / 9 = 1.11...
View Full Document

{[ snackBarMessage ]}

### Page1 / 2

PracticeQuestions6Answers - 2 2 2 1 2 4 4 2 Var X Var X Var...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document
Ask a homework question - tutors are online