Question

Problems 20 – 22. A 95% two-sided confidence interval for μ which has been calculated using the R function t.test() turns out to be (0, 1).

20. You can be 95% confident that μ is between 0 and 1.

(A) no (B) yes

21. A 90% two-sided confidence interval based on the same data will contain the value 0.9.

(A) cannot tell (B) no (C) yes

22. A 99% two-sided confidence interval based on the same data will contain the value 0.9.

(A) cannot tell (B) yes (C) no

Answer 1

20:

Yes, 95% confidence interval means one can be 95% confident that true population mean lies in the interval 0 and 1.

Answer: (B) yes

21:

90% confidence interval will be narrower than 95% confidence interval so we cannot be sure whether 0.9 lies in the 90% confidence interval or not.

Answer: (A) cannot tell

22:

99% confidence interval will be wider than 95% confidence interval so we can be sure that 0.9 lies in the 99% confidence interval.

Answer: (B) yes