How do I approach Machine Learning interview questions?

Machine Learning questions require understanding of core concepts and practice. PracHub provides solutions with explanations to help you master machine learning interviews.

What difficulty level is this interview question?

This is a easy difficulty Machine Learning question, commonly asked during Take-home Project rounds at Boston Consulting Group.

What role is this question designed for?

This question is commonly asked for Data Scientist candidates at Boston Consulting Group during technical interviews.

Scale and Normalize: When to Use Each Method?

Last updated: Mar 29, 2026

Quick Overview

This question evaluates a candidate's competency in feature scaling and normalization techniques within Machine Learning feature engineering, specifically the application of standardization and min-max normalization to numerical DataFrame columns.

Boston Consulting Group

Aug 4, 2025, 10:55 AM

Data Scientist

Take-home Project

Machine Learning

Feature Scaling Before Modeling (CodeSignal Notebook)

Context

You're preparing features in a notebook step before training a model. You have a pandas DataFrame df with two numeric columns: age and income.

Task

Standard-scale the age column (mean 0, variance 1).
Min-Max normalize the income column to [0, 1].
Briefly explain when you would prefer each scaler.

Assume scikit-learn is available.

Solution

Show

Comments (0)

Loading comments...

Browse More Questions

More Machine Learning•More Boston Consulting Group•More Data Scientist•Boston Consulting Group Data Scientist•Boston Consulting Group Machine Learning•Data Scientist Machine Learning