Question

1. A study of the effect of caffeine on muscle metabolism used 24 male volunteers who each underwent arm exercise tests. 12 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. Data is in:

Placebo	Caffeine
105	96
119	99
100	94
97	89
96	96
101	93
94	88
95	105
98	88
95	90
103	97
102	92

1. Provide descriptive statistics (mean, SD, median and interquartile) for each group.
2. Construct a hypothesis test that detect whether there is difference in RER between two groups at .05 significant level (show steps)
3. Construct a hypothesis test that detect whether Caffeine reduces RER compared to placebo at .05 significant level (show steps)

Answer 1

thank you