The 95% C.I. around a given sample mean is wider than the 90% C.I. around the mean. True or False and why?

A 95% confidence interval is wider than a 90% confidence interval.


The width of confidence intervals around the mean of a population are inversely proportional to the 伪-risk (the risk of stating that the ACTUAL population mean is in the C.I. when it is NOT). Therefore, the smaller the 伪-risk, the wider the C.I., where confidence = 伪 - 1.


I like to think of it as a butterfly net -- the larger the net, the less chance of missing a butterfly.