If we compute 95% confidence limits on the mean as 112.5

Question

If we compute 95% confidence limits on the mean as 112.5 - 118.4, we can conclude that
A) the probability is .95 that the sample mean lies between 112.5 and 118.4.
B) the probability is .05 that the population mean lies between 112.5 and 118.4.
C) an interval computed in this way has a probability of .95 of bracketing the population mean.
D) the population mean is not less than 112.5.

Quizplus · Accepted Answer

This choice correctly states that the confidence interval has a probability of .95 of containing the true population mean. This interpretation is in line with the definition of a confidence interval, which is an interval estimate that is likely (in this case, with 95% probability) to contain the true population parameter. Choices A and B are incorrect because they respectively suggest that the sample mean (not the population mean) and the population mean (with a probability of .05) lie within the given interval. Choice D is incorrect because the interval does not provide information about whether the population mean is less than 112.5 or not.