Which is true about a 99% confidence interval based on a given sample?
I. The interval contains 99% of the population.
II. Results from 99% of all samples will lie in this interval.
III. The interval is wider than a 95% confidence interval would be.
A) I only
B) none
C) III only
D) II only
E) II and III only

Question

Quizplus · Accepted Answer

III only. A 99% confidence interval does not imply that it contains 99% of the population or that 99% of all samples will lie within this interval. It means that if we were to take many samples and construct a confidence interval from each, 99% of those intervals would contain the true population parameter. A 99% confidence interval is wider than a 95% confidence interval because increasing confidence requires capturing more of the population variability to be more certain that the interval includes the true parameter.

Which Is True About a 99% Confidence Interval Based on a Given