Top 50 data Science Interview Questions | Data Science Aptitude Questions Answers

What is p-value and give an example?

In statistical significance testing, the p-value is the probability of obtaining a test statistic at least as extreme as the one that was actually observed, assuming that the null hypothesis is true. If the p-value is less than 0.05 or 0.01, corresponding respectively to a 5% or 1% chance of rejecting the null hypothesis when it is true (Type I error).

Display the depart numbers with more than three employees in each dept.

SELECT deptno, count(deptno)
FROM emp
GROUP BY deptno
HAVING count(*)>3;

In a single toss of 2 fair (evenly-weighted) six-sided dice, find the probability that their sum will be at most .

When you roll two dice, you have 6 possibilities for each roll (6 sides). This is 36 total combinations.
Let's list the combinations that result in sums greater than 9.
(4,6) (6,4) (5,5) (6,5) (5,6) (6,6)
That's 6 out of the 36 total possibilities. Therefore, the remaining 30/36 possibilities fulfill the less than or equal to 9 requirements. Simplifying by a factor of 6, that's 5/6 chance.

Let’s say you have a very tall father. On average, what would you expect the height of his son to be? Taller, equal, or shorter? What if you had a very short father?

Shorter. Regression to the mean

Let’s say you’re building the recommended music engine at Spotify to recommend peoplemusic based on past listening history. How would you approach this problem?

Collaborative Filtering