CompTIA Data+ (DA0-001) — Question 171

A market research firm has data sets based on surveys. A data analyst wants to know if any outliers are present in a data set. Which of the following would be the BEST method to examine the numerical variables in the data set visually and find any outliers?

Answer options

• A. Plot the linear correlations between each pair of variables and look for unusual relationships
• B. Create a bar chart for each variable and look for any distributions that are unusual.
• C. Build a scatter plot of each variable and look for observations that are out of place.
• D. Order each variable in a spreadsheet from lowest to highest and look for unusual numbers at the beginning or at the end of the list.

Correct answer: C

Explanation

The correct answer is C because scatter plots effectively visualize the relationship between two numerical variables and can highlight outliers that deviate significantly from the trend. Options A and B do not specifically target the identification of outliers, as correlations and bar charts are less effective for this purpose. Option D, while useful for spotting extreme values, may not provide a clear visual representation of outliers compared to a scatter plot.