10.14 Energy drinks: health risks and toxicity A study was carried out in Saudi Arabia in which 31 male university students (18 overweight/obese and 13 having normal weight) were enrolled from December 2013 to December 2014 (www.annsaudimed.net). The heart rate variability was significantly less in obese subjects as compared to subjects with normal weight at 60 minutes after consuming an energy drink as indicated by the mean heart rate range MHRR (P-value = 0.012).

a. The conclusion was based on a significance test comparing means. Define notation in context, identify the groups and the population means and state the null hypothesis for the test.

b. What information you are not able to obtain from the P-value approach which you could learn if the confidence interval comparing the means was provided?