When drawing a conclusion about the 95% confidence interval with a known population standard deviation, a researcher would state that there is a ______.
A) .95 probability that a confidence interval contains the median score for the population
B) 95% probability that a confidence interval contains the mean score for the population
C) .95 probability that a confidence interval contains the mean score for the population
D) .05 probability that a confidence interval contains the mean score for the population

Question

Quizplus · Accepted Answer

A 95% confidence interval means that if we took repeated samples and constructed 95% confidence intervals for each sample, about 95% of those intervals would contain the true population mean. This does not apply to the median score, only the mean. Choice A is incorrect because we are estimating the mean, not the median. Choice B is imprecise because we are estimating the mean, not stating a probability. Choice D is incorrect because a 95% confidence interval does contain the population mean with a 95% probability, not a 5% probability.

When Drawing a Conclusion About the 95% Confidence Interval with a Known