RESEARCH SCENARIO 2 "Beta Blockers" for Performance Anxiety: Over the last few decades, beta blockers, a common treatment for high blood pressure, have been prescribed for performance anxiety as a tool to reduce sympathetic activity (e.g., sweating, increased heart rate) in the body. The findings regarding this method have been mixed. Many argue that manipulating the sympathetic nervous system will be useless if an individual does not have proper inhibition systems such as the parasympathetic and GABA systems. Although many have reported reductions in anxiety, others have reported no effect and, in some cases, negative effects. We want to study whether or not beta blockers have any effect on anxiety (positive or negative). We review the literature and determine that the aggregate (average) anxiety change from beta blockers is 0 points (no change) on an anxiety measure, with a standard deviation of 4.6. A sample of 36 adults take a beta blocker and report their anxiety level before and after taking the drug. They report an average reduction in anxiety of -1.25 points. Run a two-tailed hypothesis test, with alpha = 0.05

6. (Step 1): Identify the two comparison populations. 1 = ? 2 = ? 7. (Step 2): State the null & research hypothesis (in symbols AND words) 8. (Step 3): State the parameters (mean and standard error) of the comparison distribution. = ? _M = ?

9. (Step 4) Calculate the critical values (alpha level & z-critical). Identify rejection region (in terms of z-scores, when would you reject H₀?). 10. (Step 5) Calculate the test statistic (z observed). 11. (Step 6) Is z-observed greater than or less than your z-critical (in mathematical terms)? State your research decision and interpret briefly (in plain language). 12. What if the average anxiety level in the sample actually increased by 2 points? How would this change Step 5 and 6? (State new observed z statistic and decision).