Chapter 16, Problem 16E

Confidence intervals, again Several factors are involved in the creation of a confidence interval. Among them are the sample size, the level of confidence, and the margin of error. Which statements are true?

1. a) For a given sample size, reducing the margin of error will mean lower confidence.
2. b) For a certain confidence level, you can get a smaller margin of error by selecting a bigger sample.
3. c) For a fixed margin of error, smaller samples will mean lower confidence.
4. d) For a given confidence level, a sample 9 times as large will make a margin of error one third as big.