Quick Answer
The answer is a box plot grouped by category. This is the correct choice because it directly visualizes the relationship between a categorical variable with three levels and a continuous target variable by displaying the distribution of the continuous data within each category side by side, showing median, quartiles, and potential outliers. On the AWS Certified Machine Learning Specialty MLS-C01 exam, this question tests your understanding of exploratory data analysis (EDA) and selecting the right plot for comparing distributions across groups, a common task before feature engineering or model selection. A frequent trap is choosing a scatter plot or line chart, which are designed for two continuous variables, not for visualizing categorical versus continuous relationships. Remember the memory tip: “Boxes for boxes” — when you have a categorical feature and a continuous target, think box plots to compare the boxes of each group.
This MLS-C01 practice question tests your understanding of exploratory data analysis. Compare every option against the stated constraints before choosing — the best answer satisfies all requirements, not just the most obvious one. After answering, compare your reasoning against the explanation and wrong-answer breakdown below. Once you have made your selection, read the full explanation to reinforce the concept and understand why each distractor is designed to mislead on exam day.
A data scientist wants to understand the relationship between a categorical feature with 3 levels and a continuous target variable. Which visualization is most appropriate?
Correlation matrix
Why wrong: Correlation is for continuous variables, not categorical.
Line chart
Why wrong: Line charts are for time series or ordered data.
Box plot grouped by category
Box plots compare distributions across categories.
Scatter plot
Why wrong: Scatter plots are for two continuous variables.
Answer choices
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
Box plot grouped by category
A box plot grouped by category (Option C) is the most appropriate visualization because it directly compares the distribution of a continuous target variable across the three levels of a categorical feature. It displays median, quartiles, and potential outliers for each group, making it ideal for understanding central tendency, spread, and skewness in a side-by-side comparison.
Key principle: Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Answer analysis
For each option: why learners choose it and why it is or isn't the right answer here.
Correlation matrix
Why it's wrong here
Correlation is for continuous variables, not categorical.
Line chart
Why it's wrong here
Line charts are for time series or ordered data.
Box plot grouped by category
Why this is correct
Box plots compare distributions across categories.
Related concept
Read the scenario before looking for a memorised answer.
Scatter plot
Why it's wrong here
Scatter plots are for two continuous variables.
Common exam traps
The trap here is that candidates often confuse the purpose of a scatter plot (for two continuous variables) with the need to compare a continuous variable across categories, leading them to choose Option D instead of recognizing that a grouped box plot is the standard tool for this task.
Detailed technical explanation
Under the hood, a box plot uses the five-number summary (minimum, first quartile, median, third quartile, maximum) and optionally identifies outliers using the interquartile range (IQR) rule (points beyond 1.5×IQR from the hinges). In exploratory data analysis, this visualization is particularly useful for detecting differences in central tendency and variance across groups, which is critical before applying statistical tests like ANOVA or building models that assume homoscedasticity.
Key takeaway
Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Real-world example
A cloud solutions architect for a retail company is evaluating services for a new workload. The correct answer here reflects best practice for the specific scenario described — not a general cloud recommendation. Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option. Cloud exam questions reward reading the constraint carefully: the same technology can be right or wrong depending on the use case.
What to study next
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Exploratory Data Analysis — study guide chapter
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FAQ
Exploratory Data Analysis — This question tests Exploratory Data Analysis — Read the scenario before looking for a memorised answer..
The correct answer is: Box plot grouped by category — A box plot grouped by category (Option C) is the most appropriate visualization because it directly compares the distribution of a continuous target variable across the three levels of a categorical feature. It displays median, quartiles, and potential outliers for each group, making it ideal for understanding central tendency, spread, and skewness in a side-by-side comparison.
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
Read the scenario before looking for a memorised answer.
About these practice questions
Courseiva creates original exam-style practice questions with explanations and wrong-answer analysis. It does not publish real exam questions, exam dumps, or protected exam content. Learn why practice questions differ from exam dumps →
Same concept, more angles
These questions test the same concept from different angles. Work through them to make sure you can recognise it however the exam phrases it.
Variation 1. A data scientist wants to visualize the correlation between a continuous feature and a binary target variable. Which plot is most appropriate?
easyWhy C: Option B is correct because a box plot shows distribution of the continuous feature across categories of the binary target, highlighting differences. Option A is wrong because a scatter plot is for two continuous variables. Option C is wrong because a histogram shows distribution of a single variable. Option D is wrong because a bar chart is for categorical vs categorical or counts.
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Last reviewed: Jun 24, 2026
This MLS-C01 practice question is part of Courseiva's free Amazon Web Services certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the MLS-C01 exam.
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