Machine Learning / AI

Tell us about your practical experience with A/B testing

Python task: determine if there is a vertical axis of symmetry for a given list of points on the plane.

In what order are SQL operators executed: SELECT, FROM, JOIN, WHERE, GROUP BY, HAVING, LIMIT?

SQL task: retrieve the last N purchases of each user.

SQL task: find salespeople who served multiple clients from the same city in 2022

Python task: find the index of the first non-repeating character in a string (First Unique Character)

How would you calculate the variance for a sample of 20 employees? And how is your estimate better than a random number 3?

What is the variance of a random variable?