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Statistics & DataChallengeHypothesis Tests

Hypothesis Tests · Challenge problem

In an A/B test, 45 of 200 users shown design B click a button. Design A is also shown to 200 users. The pooled two-proportion zz test, z=p^A−p^Bp^(1−p^)(1200+1200)z = \dfrac{\hat p_A - \hat p_B}{\sqrt{\hat p(1-\hat p)(\tfrac1{200} + \tfrac1{200})}} with p^\hat p the pooled proportion, rejects H0 ⁣:pA=pBH_0\!: p_A = p_B when ∣z∣>1.96|z| > 1.96. What is the smallest number of clicks on design A that leads to rejection with p^A>p^B\hat p_A > \hat p_B?