{"blocks": [{"key": "d4f99d8b", "text": "Scenario", "type": "header-two", "depth": 0, "inlineStyleRanges": [], "entityRanges": [], "data": {}}, {"key": "085246cc", "text": "Analyst case study – evaluate the business impact of a marketing campaign waiving first-year annual fees.", "type": "unstyled", "depth": 0, "inlineStyleRanges": [], "entityRanges": [], "data": {}}, {"key": "45f18c3f", "text": "Question", "type": "header-two", "depth": 0, "inlineStyleRanges": [], "entityRanges": [], "data": {}}, {"key": "9953b52c", "text": "Design an A/B test to measure incremental card acquisitions and spend. Specify primary metrics, guardrail metrics, sample-size calculation, and post-experiment analysis steps.", "type": "unstyled", "depth": 0, "inlineStyleRanges": [], "entityRanges": [], "data": {}}, {"key": "031c0974", "text": "Hints", "type": "header-two", "depth": 0, "inlineStyleRanges": [], "entityRanges": [], "data": {}}, {"key": "85e769b6", "text": "Conversion rate, revenue lift, CUPED or stratification to increase power.", "type": "unstyled", "depth": 0, "inlineStyleRanges": [], "entityRanges": [], "data": {}}], "entityMap": {}}