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Calculate Expected Users Adopting Wallet Feature

CoinbaseData Scientist · Technical Screen
EasyData ScientistTechnical ScreenStatistics & Math

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This interview question evaluates statistical assumptions, formulas, estimation strategy, uncertainty, edge cases, and interpretation in a realistic interview setting. A strong answer for Calculate Expected Users Adopting Wallet Feature states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.

Scenario

For N users, each independently adopts the wallet feature with probability p.

Question

Derive the expected number of users who adopt the wallet feature. 2) Compute the probability that at least one user adopts it. 3) State the core statistical assumption used in these calculations. 4) Given that at least one of two specific users adopted the feature, what is the probability both of them did?

Hints

Apply linearity of expectation, Bernoulli independence, complement rule, and conditional probability.