Question

based on the data, the students inferred that stretching before climbing stairs lowers the heart rate because oxygen gets delivered to the muscles.
what evidence justifies the students explanation?
a the average resting heart rate is the same in both trials.
b the heart rate after stretching is lower than the resting heart rate.
c the heart rate after climbing stairs is lower for students who stretched first.
d the heart rate after climbing stairs is higher than the resting heart rate in both trials.

Explanation:

Step1: Analyze Option A

The average resting heart rate is \(85.0\) bpm in both trials (with and without stretching). This shows the same resting heart rate in both trials.

Step2: Analyze Option B

The heart rate after stretching (\(102.5\) bpm) is not lower than the resting heart rate (\(85.0\) bpm).

Step3: Analyze Option C

The heart rate after climbing stairs for students who stretched first (\(148.5\) bpm) is not lower than for those who didn't (the non - stretched one is \(160.0\), but the comparison in the option is wrong as it's about climbing stairs heart rate vs resting, not as described in the option).

Step4: Analyze Option D

The heart rate after climbing stairs (\(148.5\) and \(160.0\)) is higher than the resting heart rate (\(85.0\)) in both trials, but this is not what the option says (it wrongly compares climbing stairs heart rate in a wrong context).

Answer:

A. The average resting heart rate is the same in both trials.