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."
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...
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)...
Compute p-values, probabilities, and regularization choices
Answer all parts. A) Hand‑compute a two‑sided p‑value comparing two means using Welch’s t‑test. Sample A: n1=20, mean1=5.2, sd1=1.1. Sample B: n2=24, ...
Characterize metric distribution and quantiles
KPI Analysis: Per-Video Watch Time (seconds) You are evaluating a pilot dataset for the KPI "per‑video watch time" (in seconds). The dataset (n = 20) ...
Set the Group Call participant cap
We must set a maximum participants cap K for Group Calls. You have telemetry at the call level: calls(call_id, start_ts, participants_count, video_on_...
Test two models' proportions for significance
Two search models, A and B, were each used once by 100 distinct users (one query per user). Success is defined per query by your composite metric (suc...
Diagnose and fix a flight-delay modeling setup
Flight Delay Modeling: Binary Target, Features, and Diagnostics You are modeling the probability that a flight arrives with a delay greater than 15 mi...
Choose tests under non‑normal, unequal variance
Heavy-Tailed, Heteroskedastic Metrics in A/B Tests (AOV example) Context: You are comparing two groups in an A/B test on a spend metric (e.g., Average...
Compute cluster-aware significance and sequential corrections
Cluster-Randomized Tipping UI Experiment: Power, Sequential Testing, and Multiplicity Context: A creator-level (cluster) randomized experiment evaluat...
Quantify base-rate dilution in CTR
Weighted-Average CTR and Volume Requirements You are assessing the impact of introducing a new high-CTR event notification into an existing stream of ...
Derive E[X^2] from mgf e^{t^2}
Identify Distribution and Compute E[X^2] from an MGF You are given a random variable X with moment-generating function (mgf): - M_X(t) = E[e^{tX}] = e...
Find minimal a for PSD of 3x3 matrix
PSD threshold for a 3×3 matrix with constant off-diagonal entries You are given the symmetric matrix with ones on the diagonal and a constant real val...
Analyze DAU comments distribution and resampling
Consider the metric comments_per_DAU (number of comments a daily active user makes in a day). a) Shape: Describe and justify the expected distribution...
Estimate price–ETA trade-offs causally
Causal Effect Between Price and Expected Arrival Time (ETA) in a Real-Time Ride-Hailing Marketplace Objective Estimate the causal relationship between...
Derive and validate DID for staggered rollout
Causal Effect of a Staggered Adoption Policy Across EU Regions You cannot randomize. An intervention is rolled out at different dates across EU region...
Choose robust metrics for skewed comments
Robust central tendency and inference for zero‑inflated, heavy‑tailed counts You are evaluating an A/B test on per‑user daily comment counts. The outc...
Analyze HT vs HH stopping-time probabilities
Coin-Flip Stopping Game: HT vs HH You repeatedly flip a coin until either the pattern HT appears (Player A wins) or the pattern HH appears (Player B w...
Evaluate payback and sensitivity for solar vs ethanol pilots
Renewable Pilot Evaluation — Payback and Sensitivity Context Two 1-year-operated pilot plants are being considered to add renewable capacity. Assume s...
Sketch function from derivatives and limits
Function analysis with derivative and concavity constraints Context (clarified): Assume f: R → R is differentiable everywhere and twice differentiable...