In constructing a confidence interval estimate of the popula

In constructing a confidence interval estimate of the population mean you decide to select 49 random observations to get your point estimate of the mean (sample mean). Your friend is also constructing a similar confidence interval estimate but decides to use a sample size of 36 random observations. Which of the following is true?

  Your friend’s confidence interval estimate has a greater degree of confidence.

  Your confidence interval estimate has a greater degree of confidence.

Your confidence interval estimate is narrower.

Your confidence interval estimate is wider.

28. The width of a confidence interval estimate for a proportion will be:

Narrower for 99% confidence level than for a 95% confidence level

Wider for a sample size of 100 than for a sample size of 75

Narrower for 90% confidence level than for a 95% confidence level

Narrower when the sample proportion is .50 than when the sample proportion is .20

1.429 points   

QUESTION 29

29. The value of “Z” chosen for constructing (calculating) the confidence interval estimate is determined by

The sample size

The standard deviation

Level of confidence

Correction factor

30. As the sample size increases the standard error of the mean increases?

True

False

31. As the sample size increases, the variation of the sample mean from the population mean becomes larger and larger?

True

False

Solution

27.

A greater sample size lessens the standard error (s/sqrt(n)), hence, makes the confidence interval NARROWER.

Thus, OPTION C: Your confidence interval estimate is narrower.

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28.

Greater confidence levels lead to WIDER confidence interval.

Thus, OPTION C: Narrower for 90% confidence level than for a 95% confidence level.

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29. C. Level of confidence

30. B. False (standard error = s / sqrt(n) )

31. B. False, for the same reason as 30.