Confidence intervals 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?...

Confidence intervals 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?

 a) For a given sample size, higher confidence means a smaller margin of error.

 b) For a specified confidence level, larger samples provide smaller margins of error.

 c) For a fixed margin of error, larger samples provide greater confidence.

 d) For a given confidence level, halving the margin of error requires a sample twice as large.