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Statistics & Math Interview Questions

Practice 9403 coding, system design and machine learning questions from 546 companies, sorted by role, topic and interview round. Every question has step-by-step hints, a code runner that supports 8 languages and an AI mentor; members also get the full solution walkthrough.

9403
Questions
546
Companies
11
Topics
8
Languages

Showing 31–60 of 218 results

  • Capital OneMediumData Scientist
    Compute unit economics and insurance break-even

    This question evaluates a candidate's proficiency in unit economics, insurance break-even analysis, expected-value modeling, churn effects, pricing versus demand trade-offs, and basic statistical inference including MLE and confidence intervals.

    Statistics & MathTechnical Screen
  • Capital OneMediumData Scientist
    Determine Factors Influencing Airline Flight Delays Statistically

    This interview question evaluates statistical assumptions, formulas, estimation strategy, uncertainty, edge cases, and interpretation in a realistic interview setting. A strong answer for Determine Factors Influencing Airline Flight Delays Statistically states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.

    Statistics & MathTechnical Screen
  • Capital OneMediumData Scientist
    Determine intersection dimension of two 4D subspaces

    This question tests the application of the Grassmann Dimension Formula to determine the possible dimensions of the intersection of two subspaces within a larger vector space.

    Statistics & MathTechnical ScreenLinear AlgebraVector SpacesSubspaces
  • Capital OneMediumData Scientist
    Evaluate ROI and payback for renewables

    This question evaluates competency in financial modeling and quantitative analysis for utility-scale renewable projects, testing skills in ROI and payback calculation, unit economics, capacity constraint analysis, sensitivity analysis, and scenario comparison.

    Statistics & MathTechnical Screen
  • Capital OneMediumData Scientist
    Evaluate payback and sensitivity for solar vs ethanol pilots

    This question evaluates quantitative financial modeling and sensitivity analysis skills—specifically expected-value computation, simple payback estimation, and scenario-based risk quantification for renewable-energy pilots.

    Statistics & MathTechnical Screen
  • Capital OneEasyData Scientist
    Find minimal a for PSD of 3x3 matrix

    This question evaluates understanding of linear algebra concepts such as eigenvalues, matrix definiteness, and spectral properties by asking for the minimal real parameter a that makes a symmetric 3×3 matrix with ones on the diagonal and constant off-diagonal entries positive semidefinite.

    Statistics & MathTechnical Screen
  • Capital OneEasyData Scientist
    How do you compute expected return for two projects?

    This question tests your ability to calculate the Expected Monetary Value (EMV) of probabilistic outcomes and apply discounting principles to evaluate competing capital investment projects.

    Statistics & MathTechnical ScreenStatisticsFinanceProbability
  • Capital OneMediumData Scientist
    How to Analyze and Reduce Airline Flight Delays

    This interview question evaluates statistical assumptions, formulas, estimation strategy, uncertainty, edge cases, and interpretation in a realistic interview setting. A strong answer for How to Analyze and Reduce Airline Flight Delays states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.

    Statistics & MathTechnical Screen
  • Capital OneMediumData Scientist
    Maintain profit margin with new product line

    This question evaluates competence in cost-volume-profit analysis, algebraic modeling of profit margins, and unit economics when adding a new product line.

    Statistics & MathTechnical Screen
  • Capital OneEasyData Scientist
    Match prior-year profit with new fixed costs

    This question tests the ability to model financial profitability by balancing fixed cost increases against variable profit contributions to maintain a target net income.

    Statistics & MathTechnical ScreenAlgebraFinancial ModelingCVP Analysis
  • Capital OneMediumData Scientist
    Optimize profitability for coding contract decisions

    This question evaluates competency in quantitative cost modeling, scheduling, and probabilistic sensitivity analysis within the statistics & math domain, focusing on profit optimization and resource-allocation decisions relevant to a data scientist role.

    Statistics & MathTechnical Screen
  • Capital OneMediumData Scientist
    Quantify database bug cost/benefit

    This question evaluates a candidate's ability to perform cohort-based financial impact analysis and basic statistical arithmetic to quantify revenue and cost deltas caused by registration-state errors.

    Statistics & MathTechnical Screen
  • Capital OneMediumData Scientist
    Sketch function from derivatives and limits

    This question evaluates understanding of calculus concepts—derivatives, concavity, limits, and continuity—and the ability to interpret derivative sign patterns to infer monotonicity and locate extrema.

    Statistics & MathTechnical Screen
  • CargurusMediumData Scientist
    Assess a Distribution and Derive Coin-Toss Expectations

    This problem tests the ability to distinguish between Bernoulli and Binomial processes, calculate expected values and variances, and validate model assumptions based on observed sample data.

    Statistics & MathTechnical ScreenProbabilityStatisticsMLE
  • CiscoHardSoftware Engineer
    Formalize a Minimum-Trip Transport Puzzle with Horses and Ladders

    Model a horses-and-ladders transport puzzle by clarifying legal moves, tracking resource state, and proving a minimum-trip plan is optimal.

    Statistics & MathTechnical Screen
  • CitadelMediumData Scientist
    Calculate Probability of Third Card Being an Ace

    Evaluates conditional probability with cards drawn without replacement after observing at least one Ace. Strong answers define the conditioning event, account for the number of Aces among the first two cards, and compute the probability that the third card is an Ace as 49/825.

    Statistics & MathTechnical Screen
  • CitadelMediumSoftware Engineer
    Choose 200 of a Million Records to Label, Improving on Uniform Random Sampling

    Tests the ability to define data informativeness under extreme budget constraints (selecting 200 out of 1,000,000 records) and design a scalable, one-shot sampling strategy that outperforms uniform random sampling in coverage and diversity.

    Statistics & MathTechnical ScreenActive LearningSamplingClustering
  • CitadelMediumData Scientist
    Compute P(third Ace | Ace in first two)

    This question evaluates understanding of conditional probability, dependence versus independence, symmetry arguments, and combinatorial reasoning in sampling without replacement.

    Statistics & MathTechnical Screen
  • CitadelHardSoftware Engineer
    Compute Statistics from a Frequency Array

    Compute count, minimum, maximum, mean, median, mode, and population standard deviation directly from a 256-bin frequency array. Use weighted moments and cumulative ranks without expanding samples, define empty-data behavior and ties, and address overflow and numerical precision.

    Statistics & MathTechnical Screen
  • CitadelMediumData Scientist
    Compute variance of trading profits

    This interview question evaluates statistical assumptions, formulas, estimation strategy, uncertainty, edge cases, and interpretation in a realistic interview setting. A strong answer for Compute variance of trading profits states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.

    Statistics & MathTechnical Screen
  • CitadelMediumData Scientist
    Derive Coefficient and Covariance in Regression Analysis

    Evaluates statistics fundamentals across equicorrelation constraints, reverse regression slopes, covariance of uniform order statistics, and change of variables. Strong answers use positive semidefinite matrices, simple-regression identities, order-statistic expectations, and Jacobian transformations.

    Statistics & MathTechnical Screen
  • CitadelEasyData Scientist
    Diagnose and Validate a Regression Model

    Work through regression model validation from split design and leakage prevention to residual analysis and segment-level error checks. The solution explains MAE versus RMSE, multicollinearity, coefficient limits, and when added model complexity is worth the operational cost.

    Statistics & MathTechnical Screen
  • CitadelMediumData Scientist
    Explain multicollinearity and OLS assumptions

    Explain multicollinearity and OLS assumptions evaluates statistical assumptions, formulas, estimation strategy, uncertainty, edge cases, and interpretation in a realistic interview setting. A strong answer states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.

    Statistics & MathTechnical Screen
  • CitadelEasyData Scientist
    Find constant minimizing absolute error

    This question tests the understanding of L1 loss minimization and the statistical property that the median is the optimal point estimator under absolute error loss.

    Statistics & MathTechnical ScreenStatisticsOptimizationMedian
  • CoinbaseEasyData Scientist
    Calculate Expected Users Adopting Wallet Feature

    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.

    Statistics & MathTechnical Screen
  • CoinbaseEasyData Scientist
    Calculate Expected Users Linking Coinbase Wallets

    Coinbase probability question covering Bernoulli indicators, expected wallet links, complement rule for at least one success, and conditional probability for two users linking wallets.

    Statistics & MathTechnical Screen
  • CoinbaseEasyData Scientist
    Model Feature Adoption Probability for Users

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

    Statistics & MathTechnical Screen
  • CoinbaseHardData Scientist
    Solve the 12-coin balance puzzle

    This question evaluates understanding of combinatorial reasoning, information theory, and decision-tree construction for identifying a single counterfeit coin and whether it is heavier or lighter using constrained balance-scale observations.

    Statistics & MathTechnical Screen
  • DRWMediumData Scientist
    Differentiate sample vs population standard deviation

    This interview question evaluates statistical assumptions, formulas, estimation strategy, uncertainty, edge cases, and interpretation in a realistic interview setting. A strong answer for Differentiate sample vs population standard deviation states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.

    Statistics & MathTechnical Screen
  • DatabricksHardData Scientist
    Explain Linear Regression Assumptions

    This question tests the candidate's mastery of the Gauss-Markov theorem and the consequences of violating Ordinary Least Squares (OLS) assumptions in real-world data science workflows.

    Statistics & MathTechnical ScreenStatisticsRegressionOLS