1. What is the primary purpose of utilizing control groups in clinical research? - A) To provide a standard for comparison - B) To increase the sample size - C) To test the placebo effect - D) To reduce the cost of the study Answer: A) To provide a standard for comparison. Rationale: Control groups are used to compare outcomes with the experimental group to determine the effect of the intervention. 2. In a study measuring the time until recovery from surgery, what type of statistical analysis is most appropriate? - A) T-test - B) Chi-square test - C) Survival analysis - D) Regression analysis Answer: C) Survival analysis. Rationale: Survival analysis is used when the outcome is the time until an event occurs. 3. Which measure of central tendency is most affected by extreme values? - A) Mean - B) Median - C) Mode - D) Range Answer: A) Mean. Rationale: The mean takes into account all values, so it is influenced by outliers. 4. What does a p-value indicate in hypothesis testing? - A) Probability of the null hypothesis being true - B) Probability of the alternative hypothesis being true - C) Probability of observing the data if the null hypothesis is true - D) Probability of the study being replicated Answer: C) Probability of observing the data if the null hypothesis is true. Rationale: The p-value measures the strength of evidence against the null hypothesis. 5. In a study comparing two medications, what type of error occurs if a