Google

To illustrate a confidence interval, suppose a sample of $$20$$ university students provides a mean calorie estimate for a cookie of $$200$$, with a $$95\%$$ confidence interval ranging from $$160$$ to $$240$$. This indicates that there is a high probability ($$95\%$$) that the true mean calorie estimate for the entire population of university students falls somewhere between $$160$$ and $$240$$. Furthermore, this interval allows for hypothesis testing; any hypothetical population mean outside of this $$160$$ to $$240$$ range (such as a hypothetical value of $$250$$) would be considered statistically significantly different from the sample mean at the $$.05$$ alpha level.

Example of a Confidence Interval

If a sample provides a 95% confidence interval ranging from 160 to 240 for a mean estimate, how would a hypothetical population mean of 250 be evaluated?

Learn Before

Related