A past coaching client of mine interviewed for an entry-level Data Science job in Los Angeles that paid $110k per year.
Here's the 19 interview questions they were asked:
(how many of these could you answer?)
𝐒𝐭𝐚𝐭𝐢𝐬𝐭𝐢𝐜𝐬 🔢
1. Explain the difference between population variance vs sample variance
2. Describe a p-value to a 13-year-old (8th grader)
3. What Does an R-Squared Value of 0.9 Mean?
𝐒𝐭𝐚𝐭𝐢𝐬𝐭𝐢𝐜𝐬 (Continued) 🔢
4. What are some metrics to evaluate how predictive your logistic regression model is?
5. Can you explain precision vs. recall? How does that relate to an ROC curve?
𝐒𝐐𝐋 ⚙️
6. What is a database view?
7. What's the difference between a primary key & a foreign key?
8. Have you had to troubleshoot a slow query before? How did you do it?
9. When should you use a Sub-Query vs. CTE?
𝐒𝐐𝐋 (Continued) ⚙️
10. Can you write a SQL query to find the 3-day rolling average?
(very similar to this Twitter SQL interview question on