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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 439 results

  • C3 AIMediumData Scientist
    Explain Training R-Squared After Adding a Random Feature

    Prove that ordinary training R-squared cannot decrease when adding a feature, while adjusted and test-set R-squared can.

    Statistics & MathOnline Assessment
  • C3 AIMediumData Scientist
    Explain the Gaussian Distribution and Its Limits

    Tests a candidate's mathematical understanding of the Gaussian distribution, key theoretical properties such as affine closure and the Central Limit Theorem, and the ability to diagnose and handle non-normal distributions in real-world modeling.

    Statistics & MathTechnical ScreenStatisticsProbabilityAnomaly Detection
  • CVS HealthMediumData Scientist
    Compute A/B significance, CI, and power

    This question evaluates proficiency in statistical inference for A/B testing—specifically two-proportion z-tests, construction of confidence intervals with unpooled standard errors, sample-size and power calculations, and multiple-comparison correction via Bonferroni.

    Statistics & MathOnline Assessment
  • CVS HealthMediumData Scientist
    Explain p-value and choose correct test

    This question evaluates a candidate's understanding of statistical inference, hypothesis testing, and robust test selection, focusing on p-value interpretation and choosing between paired vs independent and parametric vs rank-based tests.

    Statistics & MathTechnical Screen
  • Capital OneEasyData Scientist
    Calculate Annual Profit of Credit Card Portfolio

    Evaluates annual profit calculation for a credit-card portfolio with monthly and annual revenue and cost components. Strong answers annualize figures, compute per-card profit, and scale to portfolio profit.

    Statistics & MathHR Screen
  • Capital OneEasyData Scientist
    Calculate Incremental Customers for Marketing Spend Justification

    Evaluates incremental customer calculations for partnership marketing spend justification. Strong answers derive break-even customers for fixed spend and required volume for variable-cost campaigns against a profit target.

    Statistics & MathHR Screen
  • Capital OneMediumData Scientist
    Calculate break-even new customers for a 30% Rent-a-Home discount

    A Capital One data-scientist technical screen on break-even and unit economics for a 30%-off Rent-a-Home promotion. You set up and solve the break-even equation for incremental new customers, size it against the 2M cardholder base, then re-solve under spend-uplift assumptions and explain why the required count nearly doubles.

    Statistics & MathTechnical Screen
  • Capital OneEasyData Scientist
    Calculate first-year profit margin

    This question evaluates a data scientist's quantitative reasoning about unit economics and financial metrics, including understanding fixed versus variable costs and computing profit margin as a percentage.

    Statistics & MathTechnical Screen
  • Capital OneEasyData Scientist
    Calculate profit and break-even across pricing models

    This question evaluates understanding of unit economics, break-even analysis, and pricing-model effects on profitability by requiring computation of revenue, variable and fixed costs, and profit under per-GB and two-tier pricing scenarios.

    Statistics & MathTechnical Screen
  • Capital OneEasyData Scientist
    Compare average profit across mix scenarios

    This question evaluates understanding of expected value, weighted averages, and profit-margin analysis within the Statistics & Math domain for a Data Scientist role. It is commonly asked to probe quantitative reasoning about pricing and cost trade-offs, and it tests practical application of arithmetic and scenario-based profit modeling rather than abstract theoretical concepts.

    Statistics & MathTechnical Screen
  • Capital OneEasyData Scientist
    Compare average unit profit under mix shift

    This question tests the candidate's ability to calculate weighted averages and understand how changes in sales volume distribution (mix shift) affect the overall average profit per unit.

    Statistics & MathTechnical ScreenStatisticsWeighted AverageUnit Economics
  • Capital OneEasyData Scientist
    Compute Groupon unit economics and break-even

    A Capital One data science technical screen case on restaurant unit economics with a Groupon-style voucher. You compute baseline daily profit from a 20-table day, derive the break-even check for a voucher table under a $30-for-$15 offer with a 40% commission, profit a mixed 25-table day, and decompose the profit change into traffic, check size and voucher cost. Full worked arithmetic, a sensitivity solve, and the incrementality follow-ups an interviewer expects.

    Statistics & MathTechnical Screen
  • Capital OneEasyData Scientist
    Compute Optimal Die Re-roll Strategy

    This question tests the ability to calculate expected values and determine optimal decision thresholds in a multi-stage probabilistic game.

    Statistics & MathOnsiteProbabilityExpected ValueDecision Theory
  • Capital OneMediumData Scientist
    Compute and interpret 95% confidence intervals

    This question evaluates proficiency with confidence intervals, hypothesis testing for proportions and means, multiple-comparison adjustment (Bonferroni), and sample size calculations, including assessment of normal-approximation versus Wilson score methods.

    Statistics & MathOnline Assessment
  • Capital OneMediumData Scientist
    Compute credit-card portfolio profit and breakeven

    This question evaluates financial modeling, unit-economics calculation, breakeven analysis, and basic risk/expected-loss estimation relevant to a Data Scientist, testing competency in statistics & math and algebraic derivation within financial analysis.

    Statistics & MathOnsite
  • Capital OneEasyData Scientist
    Compute current annual profit

    This question evaluates numerical proficiency in financial arithmetic, unit-aware quantitative reasoning, and per-customer business-metric computation within a loyalty program context.

    Statistics & MathTechnical Screen
  • Capital OneMediumData Scientist
    Compute expansion profits and expected value

    This question evaluates financial modeling, expected-value decision-making, probability reasoning, and sensitivity analysis skills applied to revenue, variable and fixed cost interactions and contractual fee impacts, aimed at a Data Scientist role.

    Statistics & MathOnsite
  • Capital OneEasyData Scientist
    Compute incremental profit, breakeven, and revenue sensitivity

    A Capital One data scientist technical-screen case on cost accounting and profitability modeling. Candidates compute the Year-1 incremental profit of a new vegan burger line, decompose it into fixed versus variable components, derive breakeven volume, and run a ±10% sensitivity analysis.

    Statistics & MathTechnical Screen
  • Capital OneMediumData Scientist
    Compute optimal stopping in a die-rolling game

    This question evaluates a candidate's grasp of optimal stopping theory, expected value computation, and finite-horizon decision-making under uncertainty, including recognition of threshold-based policies and backward-induction reasoning relevant to data scientist roles.

    Statistics & MathTechnical Screen
  • Capital OneMediumData Scientist
    Compute profit and break-even for memberships

    This problem tests your ability to model unit economics for a subscription-based loyalty program and perform sensitivity analysis to determine the break-even point for a business intervention.

    Statistics & MathTechnical ScreenEconomicsLinear ModelingBreak-even Analysis
  • Capital OneMediumData Scientist
    Compute required output to recover 10% investment

    This question evaluates a candidate's ability to perform cost-volume-profit analysis and quantitative financial modeling, assessing skills in algebraic formulation of profit equations, capacity constraint evaluation, and derivation of generalized feasibility formulas.

    Statistics & MathTechnical Screen
  • 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 Claim Rate for Breakeven in Insurance Portfolio

    Evaluates weather-insurance portfolio profitability from premiums, servicing, regulatory costs, and expected claims. Strong answers derive break-even claim rate, segment-selection rules, and incremental profit formulas.

    Statistics & MathOnsite
  • 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 OneHardData Scientist
    Diagnose and fix a flight-delay modeling setup

    This question evaluates proficiency in statistical modeling for binary outcomes, including concepts such as appropriate model choice and link functions, categorical encoding, ETL-driven data quality issues, multicollinearity diagnostics (e.g.

    Statistics & MathOnsite
  • Capital OneEasyData Scientist
    Differentiate fixed and variable costs with examples

    This question evaluates understanding of cost classification and unit economics—specifically the distinction between fixed and variable costs—and the competency to apply those concepts within a subscription streaming business context.

    Statistics & MathHR Screen
  • Capital OneMediumData Scientist
    Estimate Default Rates Using Logistic Regression Model

    This interview question evaluates statistical assumptions, formulas, estimation strategy, uncertainty, edge cases, and interpretation in a realistic interview setting. A strong answer for Estimate Default Rates Using Logistic Regression Model states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.

    Statistics & MathOnsite
  • 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