Data Scientist Statistics & Math Interview Questions
Practice 455 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."
Model Unique Recipients with Poisson Distribution and Test Fit
Modeling Unique Recipients per Caller Scenario You need to model the distribution of the count of unique recipients each caller contacts in a fixed ti...
Explain P-value, Confidence Interval, and Multiple Testing Adjustments
A/B Testing and Inferential Statistics for a New Product Launch You are running online A/B experiments to evaluate a new product launch. Assume standa...
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...
Explain Type I/II errors vs precision/recall
Questions 1. Define Type I error and Type II error in hypothesis testing, and map them to false positives and false negatives. 2. Explain how Type I/I...
Combine noisy thermometers; compute random-walk correlations
Problem 1: Estimating a true temperature from noisy thermometers Assume the true (fixed) temperature is an unknown constant \(\theta\). 1a) One thermo...
Compute posterior fake probability using Bayes' rule
A platform runs an automated detector to flag fake accounts. - Prior probability an account is fake: \(P(F)=0.02\). - True positive rate (sensitivity)...
Prove OLS invariance to linear transforms
You fit Model 1: y ~ X1 + X2. You also fit Model 2 using Z = [X1 − X2, X1 + X2] = X T where T = [[1,1], [−1,1]] (2×2, invertible). a) Prove that OLS p...
Compute CIs, power, and multiple testing
A/B Testing Stats: Confidence Intervals, Power, Multiple Testing, and Clustering Context: You are planning an A/B experiment on a Bernoulli outcome (c...
Estimate variance for ratio metrics
KPI Variance via Delta Method and Inference Choices for ARPU Context You run experiments where each arm produces aggregate totals per analysis unit (e...
Relate Y-on-X and X-on-Y coefficients
Relating Slopes When Reversing Simple Linear Regression Context You fit an ordinary least squares (OLS) simple linear regression with an intercept of ...
Diagnose and fix linear regression violations
Given a linear model y = Xβ + ε on 10,000 observations: (a) State all Gauss–Markov assumptions and which are needed for BLUE vs inference. (b) Show wh...
Optimize no-penalty test strategy
You face a 50-question multiple-choice test (5 options each) with total time 900 seconds. Scoring: +1 for a correct answer, 0 otherwise; there is no p...
Formulate OR model to reduce driver backtracking
Define and reduce driver ‘backtracking’ in a marketplace. First, define a quantitative backtracking metric B per driver-hour from GPS and assignment l...
Differentiate Type I vs II errors under costs
Ship/No-Ship Decision: Type I/II Errors, Cost-Sensitive Testing, Sample Size, and Multiple Testing Context You are deciding whether to ship a new disp...
Quantify improvement and compute required sample size
A/B Test on Spam Rate: Sample Size, Inference, and Practical Pitfalls Context: You are evaluating a new classifier that aims to reduce the spam rate (...
Model overdispersed counts; estimate treatment lift
Weekly posts per creator are overdispersed and zero‑inflated. In a creator‑level randomized test of a nudge: - Control: n_c=40,000 creators, total pos...
Model waiting-time abandonment via survival
Survival Modeling of Rider Abandonment During Pickup Waits Context You are modeling when a rider cancels (abandons) while waiting for pickup. Let time...
Match prior-year profit with new fixed costs
Target Profit Match with Product Mix and Added Fixed Costs m = million. You sold only Regular burgers in Year 1. In Year 2, you launch a Vegan burger ...
Identify binomial model and compute moments
Tossing N Balls Into a Cup (Independent Hits with Probability p) You toss N independent balls toward a cup. Each ball lands in the cup with probabilit...
Determine distribution of aX+b when X~N(0,1)
Linear Transform of a Standard Normal Setup - Let X ~ N(0, 1) (standard normal). - For constants a, b ∈ ℝ, define Y = aX + b. Tasks (a) What is the ex...