Interview Q&A / Data Science
Data Science interview questions
Statistics, pandas, cleaning data and exploratory analysis for analyst and data science roles.
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- How does sample size affect the margin of error in a survey?
For a proportion, margin of error is about 1.96 x sqrt(p(1-p)/n). It shrinks with the square root of n, so 1000 respondents give roughly +/- 3% and 400 give roughly +/- 5%, and reducing it further gets expensive quickly.
IntermediateQuick answer1 min read