{"blocks": [{"key": "b5fd2839", "text": "Scenario", "type": "header-two", "depth": 0, "inlineStyleRanges": [], "entityRanges": [], "data": {}}, {"key": "be053faa", "text": "You compared two large-language models in an A/B test: Model A success = 70 % (700/1000), Model B = 80 % (800/1000).", "type": "unstyled", "depth": 0, "inlineStyleRanges": [], "entityRanges": [], "data": {}}, {"key": "e80bbe59", "text": "Question", "type": "header-two", "depth": 0, "inlineStyleRanges": [], "entityRanges": [], "data": {}}, {"key": "b363396b", "text": "State hypotheses and compute a two-proportion z-statistic and p-value to decide if Model B is significantly better at α = 0.05; also give the 95 % confidence interval of the lift.", "type": "unstyled", "depth": 0, "inlineStyleRanges": [], "entityRanges": [], "data": {}}, {"key": "4e2ecabc", "text": "Hints", "type": "header-two", "depth": 0, "inlineStyleRanges": [], "entityRanges": [], "data": {}}, {"key": "10cec150", "text": "p̂ = (x1/n1 – x2/n2) / sqrt(p(1-p)(1/n1+1/n2)), where p is pooled proportion.", "type": "unstyled", "depth": 0, "inlineStyleRanges": [], "entityRanges": [], "data": {}}], "entityMap": {}}