{"blocks": [{"key": "a6b74c2c", "text": "Scenario", "type": "header-two", "depth": 0, "inlineStyleRanges": [], "entityRanges": [], "data": {}}, {"key": "7a6f4c5e", "text": "Online HackerRank first round for Spokeo DS role – timed statistics quiz", "type": "unstyled", "depth": 0, "inlineStyleRanges": [], "entityRanges": [], "data": {}}, {"key": "46a69bcb", "text": "Question", "type": "header-two", "depth": 0, "inlineStyleRanges": [], "entityRanges": [], "data": {}}, {"key": "ab3db6d0", "text": "What are the expectation and variance of a Poisson(λ) distribution? 2) Given sample size n and population standard deviation σ, write the 95% confidence interval for the population mean. 3) When should a two-sample t-test be used instead of a z-test? 4) State the Central Limit Theorem and one practical implication of it. 5) Interpret a p-value of 0.03 in the context of hypothesis testing.", "type": "unordered-list-item", "depth": 0, "inlineStyleRanges": [], "entityRanges": [], "data": {}}, {"key": "3ebf6c6d", "text": "Hints", "type": "header-two", "depth": 0, "inlineStyleRanges": [], "entityRanges": [], "data": {}}, {"key": "a9847827", "text": "Focus on core formulas, distribution properties, and correct interpretation of statistical tests.", "type": "unstyled", "depth": 0, "inlineStyleRanges": [], "entityRanges": [], "data": {}}], "entityMap": {}}