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."
Determine Appropriate Statistical Test for Comparing Means
A/B Test: Active Minutes After Two Weeks Scenario You ran a two-week A/B experiment on a new algorithm. The primary metric is user active minutes. Ass...
Determine Probability of Both Children Being Boys
Scenario A classic conditional-probability brain-teaser used in data science screens to test probabilistic reasoning and the discipline of stating ass...
Estimate Highway Billboard Impressions Using Traffic Data
Estimating Billboard Reach and Impressions Scenario An out-of-home (OOH) advertising team wants to estimate both reach (unique people who saw the ad a...
Determine Impact of New Chat-Notification on User Engagement
Scenario A product team wants to determine whether a new chat-notification design increases daily active users (DAU) in Google Workspace Chat. Task De...
Understand P-Value's Role in Product Decision-Making
Scenario You are a data scientist presenting A/B test results to non-technical executives who must decide whether to launch a product change. Question...
Evaluate Marketing Campaign's Click-Through Rate Effectiveness
Scenario A campaign currently shows a click-through rate (CTR) of 4.2%. Leadership asks whether this is good or bad relative to expectations. Task Sta...
Analyze View Distribution and Recommendation Overlap in Videos
Short-Video Platform: View Distribution and Recommendation Overlap Context You are analyzing a short-video platform. You have: - A dataset of per-vide...
Maximize Probability of Drawing Two Red Balls
Optimize Two-Basket Allocation for Red-Red Draws Setup You have 100 red balls and 100 blue balls to distribute between two baskets, A and B. Then you ...
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...
Determine Factors Influencing Airline Flight Delays Statistically
Determine Drivers of Airline Flight Delays Context You are analyzing a flight-level dataset to identify which factors most impact delays. Assume you h...
Compute and estimate Markov transition probabilities
A system is modeled as a discrete-time Markov chain over m states S = {s1, s2, ..., sm}. Part A (multi-step probabilities): - You are given a row-stoc...
Estimate bots and CI from DAU spike
Mixture Spike and Mean-Difference Inference for Daily Comments Context A product has DAU (daily active users) = 2,000,000. On day T, total comments in...
Compute and interpret quantile loss vs RMSE
Quantile (Pinball) Loss vs RMSE/MAE; Computations and Calibration You are evaluating probabilistic forecasts for a time series/ML regression task. You...
Compute expansion profits and expected value
Theme Park Expansion Profit Analysis Context You are evaluating the financial impact of capacity expansion for a theme park. Current operations and pr...
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....
Differentiate and control Type I/II errors
A/B Test Powering and Error Control (Two-Proportion Z-Test) Context: You are planning a two-arm A/B test on sign-up conversion. The current baseline c...
Compare Normal vs Poisson; test dispersion and approximate tails
You collect n=200 independent minute-level event counts with sample mean x̄=14.5 and sample variance s²=16.2. 1) Under a Poisson(λ) model, derive the ...
Derive distribution of an inverse transform
Change of Variables via the Logistic Map You are given a random variable X with density f_X supported on (0, 1). Define the strictly increasing logist...
Infer causal impact without an A/B test
Evaluate Impact of a Shipped Version on Disconnections (No A/B Holdout) Context A new client version was shipped system-wide with the goal of reducing...
Compute posterior spam risk from flags
A binary classifier flags spammy requesters. Last week the base rate of spam among all requesters was 12%. The classifier has true positive rate (TPR)...