A medical researcher measured the pulse rates beats per minu

A medical researcher measured the pulse rates (beats per minute) of a sample of randomly selected adults and found the following 95% confidence interval (based on t) for the mean pulse: [70.888,74.4910]. If the researcher has calculated a 99% confidence interval for the mean, would you the interval be shorter or longer? Explain.

Solution

99% CI will be longer than 95% CI because of higher confidence level. When we calculate CI, margin of error is higher because critical values are more extreme for higher confidence level.