Tiger Analytics Data Analyst Interview Questions and Answers

Understanding SQL joins with WHERE clause is crucial for filtering data from multiple tables effectively.

• INNER JOIN: Combines rows from two tables where there is a match. Example: SELECT * FROM Orders INNER JOIN Customers ON Orders.CustomerID = Customers.CustomerID;

• LEFT JOIN: Returns all rows from the left table and matched rows from the right table. Example: SELECT * FROM Customers LEFT JOIN Orders ON Customers.C...read more

Overfitting occurs when a model learns the noise in the training data rather than the underlying pattern.

• Overfitting happens when a model is too complex and captures noise in the training data.

• It leads to poor generalization to new, unseen data.

• Regularization techniques like L1/L2 regularization can help prevent overfitting.

• Cross-validation can be used to detect and prevent overfitting.

• Example: A decision tree wit...read more

Random forest is an ensemble learning method that builds multiple decision trees and merges their predictions.

• Random forest creates a set of decision trees from randomly selected subsets of the training data.

• Each tree in the random forest independently predicts the outcome, and the final prediction is made by averaging the predictions of all the trees.

• Random forest is effective in handling high-dimensional data an...read more

Different types of indexing include primary indexing, secondary indexing, clustered indexing, and non-clustered indexing.

• Primary indexing: Index based on the primary key of a table, typically implemented using a B-tree structure.

• Secondary indexing: Index based on a non-primary key column, allowing for faster retrieval of data based on that column.

• Clustered indexing: Physically reorders the table based on the index...read more

Permutation and combination are mathematical concepts used to count the number of possible outcomes in a given scenario.

• Permutation is the arrangement of objects in a specific order while combination is the selection of objects without considering the order.

• Permutation formula: nPr = n!/(n-r)! where n is the total number of objects and r is the number of objects selected.

• Combination formula: nCr = n!/r!(n-r)! wher...read more

Compare two arrays in python and print if both of them are same or not.

• Use the '==' operator to compare the arrays.

• If the arrays have the same elements in the same order, they are considered the same.

• If the arrays have different elements or different order, they are considered different.

• Print 'Same' if the arrays are the same, otherwise print 'Different'.

We can use statistical analysis to prove that students in higher classes are taller than those in lower classes.

• Collect height data of students from different classes

• Use statistical measures like mean, median, and mode to compare the heights of students in different classes

• Perform hypothesis testing to determine if the difference in height between classes is statistically significant

• Visualize the data using graphs...read more