Question library
Questions from real interviews. Drill any of them by voice in a couple of minutes, with an interviewer, a score and feedback.
Explain in simple terms what a p-value is.JuniorWhat is a confidence interval, and how do you interpret it correctly?JuniorWhen is it better to use the median rather than the mean to describe data?JuniorA product manager comes to you with a result: "The p-value is 0.04, so there's a 96 percent probability the new version is better." What's wrong with this interpretation, and how would you explain it to them?Mid-levelYou need to estimate the average order value and give a confidence interval, but the distribution of orders is heavily skewed, with rare very large purchases. How would you calculate it, and what would you tell the client?Mid-levelYour key metric is average order value, and it has a very heavy right tail: a few percent of customers bring in half the revenue. How would you build a confidence interval for the difference in means between two groups?Senior