A study of the effect of caffeine on muscle metabolism used eighteen male volunteers who each underwent arm exercise tests. Nine of the men were randomly selected to take a capsule containing pure...

A study of the effect of caffeine on muscle metabolism used eighteen male volunteers who each underwent arm exercise tests. Nine of the men were randomly selected to take a capsule containing pure caffeine one hour before the test. The other men received a placebo capsule. During each exercise the subject's respiratory exchange ratio (RER) was measured. (RER is the ratio of CO₂ produced to O₂ consumed and is an indicator of whether energy is being obtained from carbohydrates or fats).

The question of interest to the experimenter was whether, on average, caffeine changes RER.

The two populations being compared are “men who have not taken caffeine” and “men who have taken caffeine”

the results were as follows:

1. Develop the hypothesis,


2. Do the test


3. Write the result of the hypothesis

Extracted text: RER(%) Placebo Caffeine 105 96 119 99 100 94 97 89 96 96 101 93 94 88 95 105 98 88 Mean 100.56 94.22