An exercise physiologist is interested in the effect of exercise on heart rate.
She has the subjects walk slowly for $5$ minutes and records their heart rates. Then she has the subjects run vigorously for $5$ minutes and records their heart rates again.
The differences are recorded (heart rate after running - heart rate before running), with results below:
One-Sample T: Differences
Test of $\mu = 0$ vs. $\mu \neq 0$
|Variable||N||Mean||StDev||SE Mean||95% CI||T||P|
Why could a confidence interval be more useful in this situation than a hypothesis test?