Statistics & Math Interview Questions
Master your tech interview with our curated database of real questions from top companies.
Fake Accounts [AE]
Detecting and Managing Bad Accounts on a Social Platform 1) Probability of a Bad Account Sending Friend Requests Context: 1% of accounts are bad. Bad ...
Analyze User Comment Distribution and Sampling Effects
Scenario You are analyzing daily comment counts per user. The per-user distribution of counts is right-skewed (many zeros/low counts and a long right ...
Calculate Posterior Probability of Flagged User Being Bad Actor
Bayesian inference for abuse detection with error control Setup A platform runs a binary classifier that flags users who might be bad actors. Let: - p...
Derive Coefficient and Covariance in Regression Analysis
Correlation Structure, Regression Slopes, Covariance of Order Statistics, and Change-of-Variables You are given standard random variables and asked to...
Analyze Distribution of Daily Page Shares Per User
Engagement Distributions and Cohort Dynamics You are analyzing per-user, per-day engagement. Assume a day-level panel with all users included (inactiv...
Analyze Central Limit Theorem in User Comment Distribution
Comments per User — CLT, Expectation, SD, and 95% CI Context You are measuring how many comments each user makes in a fixed time window (e.g., one wee...
Determine Key Statistics for Article Comment Distribution Analysis
Analyzing Comment Counts per Article Context You are analyzing the number of comments each article receives on a content website. You have the full di...
Evaluate Probability of Positive User Comments and Model Performance
Social-Media Positivity: Independence and Model Comparison Context You are evaluating user comment sentiment and the performance of two models that cl...
Calculate Expected Meetings in Randomly Assigned Rooms
Random Assignment of Meetings to Rooms Scenario - There are N rooms and K meetings. Each meeting independently chooses a room uniformly at random (pro...
Prove Equal Probability Impossible with Relabeled Dice Faces
Uniform Sums from Two Relabeled Fair Dice Setup You have two fair six-sided dice. You may relabel each die's faces with integers; duplicates are allow...
Calculate Ad Insertion Statistics for Two Methods
Scenario Evaluating two ad-insertion strategies in a 100-post feed. - Option A (independent placement): Each post independently becomes an ad with pro...
Analyze Linear Regression Changes with Duplicated Observations
Linear Regression, p-values, and Chi-square with Large Samples Context You are analyzing regression and goodness-of-fit results. Consider what happens...
Estimate Family Proportions and Explain Regression Anomalies
On-site Statistics Round Task Overview You are given a population of families that have either 1, 2, or 3 children. You sample 100 children (i.e., the...
How to Update Bayesian Model for Concept Drift?
Beta–Binomial CTR Model: Prior, Likelihood, Posterior, Smoothing, Intervals, and Drift Context You are discussing statistical foundations for a Bayesi...
Estimate and Derive Regression Coefficient for X on y
Statistics & Probability Onsite — Two-Part Question Context - You have a simple linear data-generating process: y = X + ε, where X and ε are independe...
Calculate Probabilities for Mixed Reviewer Types
Scenario Two types of reviewers exist in a marketplace: - Lazy reviewers (20%) always give good reviews. - Careful reviewers (80%) give good reviews 6...
Identify Probability Distributions for Modeling Ad Clicks
Context You are interviewing for a data scientist role on an ads team. You are asked to demonstrate knowledge of common probability models for clicks,...
Determine Claim Rate for Breakeven in Insurance Portfolio
Weather-Insurance Portfolio Profitability Setup You price a 12-month weather insurance policy. Customers pay premiums upfront for the year. Each polic...
Analyze Video View Distribution: Mode, Median, Mean Comparison
Scenario You are analyzing user engagement on a short‑video sharing product. You have a distribution of “video views per user,” and you observe that a...
Estimate Population Mean and Conversion Rate Accurately
Statistical Inference: Hypothesis Tests, Confidence Intervals, Sampling Design, and Truncated Normal Estimation Context You are evaluating a set of pr...