A study compares is determining the impact of daily consumpt…

A study compares is determining the impact of daily consumption of green tea on systolic blood pressure. Among patients who began drinking green tea daily (n=23) the systolic blood pressure decreased by a mean of 5 mmHg and among patients with no dietary change (n=32) the systolic blood pressure decreased by a mean of 1 mmHg. Which of the following tests would be most appropriate to determine if the results are statistically significantly different?

Melatonin is compared to placebo for sleep in a single-group…

Melatonin is compared to placebo for sleep in a single-group randomized cross-over study (n=328). Participants are randomized to receive melatonin or placebo for 3 months and then take the other agent for 3 months following a 1-week washout period. Which of the following tests would be most appropriate to determine if this is a statistically significant difference in mean sleep latency (i.e., mean minutes to fall asleep)?