Suppose a group of 800 smokers (who all wanted to give up smoking) were randomly assigned to receive an antidepressant drug or a placebo for six weeks. Given the null hypothesis (H₀: (p_drug - p_placebo) = 0) and the alternative hypothesis (Hₐ: (p_drug - p_placebo) ≠ 0), conduct a test to see if taking an antidepressant drug can help smokers stop smoking. Use (α = 0.02).

a) The test statistic is
b) The p-value is
c) The final conclusion is