Suppose a researcher is interested in the effectiveness of a new anti-hypertensive medication in a sample of 28 clinical trial participants with high blood pressure, as measured by systolic blood pressure in millimeters of mercury (mm Hg). In a pre/post study, the researchers decide to use each participant as their own control, offering participants the drug either before or after a control period that applies the current standard of care. The difference in systolic blood pressure between the new drug treatment and the standard of care control yielded a mean of -26 mm and a standard deviation of 10.9 mm. Which one of the following is the appropriate approach to test if blood pressure under the new drug treatment is different than under the standard of care control? O t-test for two independent samples O Z-test for the difference between two proportions t-test for a paired (matched) sample O An inter-quartile range Continuing from the last question, which of the following is the 95% confidence interval of the mean difference? (-30.2, -21.8) (1.61, 11.39) O (-29.5, -22.5) (-30.2, 21.8)