numeric
False-positive risk across four variants
Experimentation & A/B Testing · Design & Power · medium · Reported interview question · 10 min
You compare four independent treatment variants with one control. Each treatment-versus-control test uses alpha = 0.05, and assume the four tests are independent. Under the global null, what is the probability of at least one false positive? Give a percentage rounded to two decimals.
Answer as a percentage, for example 12.34.
Evaluation criteria
- Uses 1 minus the probability of zero false positives
- Uses the correct method or distribution
- Shows the calculation
- Rounds as the prompt asks
Detailed grading feedback appears after you submit.
Source
Adapted from a publicly reported interview question on StrataScratch(opens in a new tab).
Your answer
%
Commas, currency symbols and a trailing percent sign are fine. Answers within ±0.15 % of the expected value are accepted.
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