The width of a confidence interval estimate for a proportion will be:
A)narrower for 90% confidence than for 95% confidence.
B)wider for a sample size of 100 than for a sample size of 50.
C)narrower for 99% confidence than for 95% confidence.
D)narrower when the sample proportion if 0.50 than when the sample proportion is 0.20.

Question

Quizplus · Accepted Answer

A confidence interval is narrower for a lower confidence level (90%) compared to a higher confidence level (95%) because less certainty is required.

The Width of a Confidence Interval Estimate for a Proportion