Data Scientist Statistics & Math Interview Questions
Practice 471 real Statistics & Math interview questions for Data Scientist roles. From companies including Meta, Capital One, Google, Amazon, Uber.
"I got asked a hardcore MCM DP question and I saw it on PracHub as well. Solved that question in 5 minutes. Without PracHub I doubt I could solve it in 5 hours. Though somehow didn't get hired, perhaps I guess I solved it too fast? /s"
"Believe me i'm a student here jn US. Recently interviewed for MSFT. They asked me exact question from PracHub. I saw it the night before and ignored it cause why waste time on random sites. I legit wanna go back and redo this whole thing if I had chance. Not saying will work for everyone but there is certainly some merit to that website. And i'm gonna use it in future prep from now on like lc tagged"
"10 years of experience but never worked at a top company. PracHub's senior-level questions helped me break into FAANG at 35. Age is just a number."
"I was skeptical about the 'real questions' claim, so I put it to the test. I searched for the exact question I got grilled on at my last Meta onsite... and it was right there. Word for word."
"Got a Google recruiter call on Monday, interview on Friday. Crammed PracHub for 4 days. Passed every round. This platform is a miracle worker."
"I've used LC, Glassdoor, and random Discords. Nothing comes close to the accuracy here. The questions are actually current — that's what got me. Felt like I had a cheat sheet during the interview."
"The solution quality is insane. It covers approach, edge cases, time complexity, follow-ups. Nothing else comes close."
"Legit the only resource you need. TC went from 180k -> 350k. Just memorize the top 50 for your target company and you're golden."
"PracHub Premium for one month cost me the price of two coffees a week. It landed me a $280K+ starting offer."
"Literally just signed a $600k offer. I only had 2 weeks to prep, so I focused entirely on the company-tagged lists here. If you're targeting L5+, don't overthink it."
"Coaches and bootcamp prep courses cost around $200-300 but PracHub Premium is actually less than a Netflix subscription. And it landed me a $178K offer."
"I honestly don't know how you guys gather so many real interview questions. It's almost scary. I walked into my Amazon loop and recognized 3 out of 4 problems from your database."
"Discovered PracHub 10 days before my interview. By day 5, I stopped being nervous. By interview day, I was actually excited to show what I knew."
"I recently cleared Uber interviews (strong hire in the design round) and all the questions were present in prachub."
"The search is what sold me. I typed in a really niche DP problem I got asked last year and it actually came up, full breakdown and everything. These guys are clearly updating it constantly."
Assess a Distribution and Derive Coin-Toss Expectations
Strengthen statistics fundamentals by assessing which distributions plausibly fit a finite sample and deriving coin-toss moments. Practice checking da...
Narrow a confidence interval for a mean
You have a simple random sample with n = 100 and sample mean 100. The current 95% CI for the population mean is 100 ± 10, which a PM says is too wide....
Infer distribution and choose robust statistics
This question evaluates a candidate's ability to infer underlying distributions from summary statistics and apply robust statistical reasoning includi...
Derive MLEs and conditional Normal distributions
Normal and Bivariate Normal: PDFs/CDFs, MLEs, Conditioning, and Unbiased Variance Setup - Let X1, …, Xn be i.i.d. Normal(μ, σ²). - Independently, let ...
Calculate CI and Test Correlation Under Normality
Inference on a Mean, Significance of a Correlation, and a Normal Quantile Assume standard parametric conditions (normality as stated). Show formulas, ...
Compute incremental profit, breakeven, and revenue sensitivity
Question You are evaluating whether to add a vegan burger line in Year 1. Use the following assumptions (m = million): - Fixed training cost: $60m/yea...
Explain mixed models and fixed vs random effects
In an applied DS setting, you are modeling an outcome (e.g., watch time per session, conversion, or rating) across multiple entities (e.g., users, cre...
Solve probability and expectation problems
Probability and Statistics Mini-Set Context: Answer each item independently. Unless otherwise specified, assume independence and uniform randomness; d...
Find the Two Heaviest Balls with Minimum Comparisons
Find the Two Heaviest Balls with Minimum Comparisons There are 32 balls with distinct weights. A comparison reveals which of two balls is heavier. Det...
Design human review to estimate model accuracy
Design human review to estimate model accuracy You need to estimate the accuracy of an ML classifier on a population of subjects. You can only afford ...
Choose and Explain a Classical Hypothesis Test
Choose and Explain a Classical Hypothesis Test Explain null and alternative hypotheses, significance level, p-value, Type I error, and Type II error. ...
Analyze survey with gender imbalance
Analyze survey with gender imbalance Scenario You ran a user survey to measure satisfaction with a new product feature. Each respondent reports: - gen...
Analyze Knights-and-Knaves Dialogue Variants
Analyze Knights-and-Knaves Dialogue Variants Knights and Knaves: Two Statements from B Context On an island, every person is either a knight (always t...
Solve quantitative word and algebra problems
Quantitative Mini-Problems (Independent) Solve each problem independently. Show your setup clearly. Use standard unit conversions and give exact value...
Interpret p-values and common pitfalls
In a Fraud Data Science interview, you are asked “some p-value questions.” Answer the following in a fraud/experimentation context: 1) Define a p-valu...
Compute and interpret 95% confidence intervals
Answer all parts. Show formulas and intermediate values. A) An A/B test measures conversion: Variant A has 410 conversions out of 5000 visitors; Varia...
Define and sample a truncated normal
Define the truncated normal Z | a < Z < b for Z ~ N(0,1): write the normalized pdf and cdf. Then design efficient samplers for three cases: (i) a = 1,...
Test if one value comes from N(μ,σ²)
This question evaluates understanding of hypothesis testing and statistical inference, specifically the formulation and interpretation of a z-statisti...
Derive lower bound for equicorrelation rho
Equicorrelation Matrix PSD Condition Setup Consider zero-mean, unit-variance random variables whose pairwise correlations are all equal to a common va...
Test conversion difference and adjust for clustering
Using aggregated results for the 7‑day window 2025‑08‑26..2025‑09‑01, evaluate statistical significance and power for conversion uplift, accounting fo...