Statistical Inference Practice Test

Researchers investigate the effect of a new statin on LDL cholesterol levels. In a clinical trial, the mean difference in LDL reduction between the statin group and the placebo group was 25 mg/dL. The 95% confidence interval for this mean difference was calculated to be (15 mg/dL, 35 mg/dL).

A study is designed to determine if a new educational intervention improves medical student scores on a standardized exam. The researchers set the significance level (α) to 0.05. After the intervention, they find that the intervention group scores significantly higher than the control group (p=0.04) and conclude the intervention is effective. However, in reality, the intervention has no true effect on exam scores.