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Detailed Explanations

A detailed answer review with side-by-side rationale, distractor analysis, related questions, and weak-topic practice.

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Applying t-tests

Correct: D
Your answer Not answered Answer this in practice or the daily question to sync here.
Correct answer D Whether means differ under a stated hypothesis
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What is a t-test commonly used to evaluate in data analysis?

A Whether two categorical variables are independent
B Whether missing values are missing completely at random
C Whether a model has the highest AUC
D Whether means differ under a stated hypothesis
1. Answer captured 2. Key checked 3. Rationale review 4. Retry weak topic

Detailed explanation

Catalog rationale

Correct answer: D

A t-test is used when the question is about a mean or a difference in means for continuous measurements. It is not the right tool for categorical count data or classifier ranking metrics.

Key concept Applying t-tests

CompTIA DataAI

Exam tip Map the requirement to the managed CompTIA capability.

Eliminate services that solve infrastructure, data movement, or routing when the stem asks for AI model access or governance.

CompTIA service references

01 CompTIA DataAI 01 Mathematics and statistics 01 Statistical methods 01 Applying t-tests

Why the wrong answers are wrong

A

Incorrect. Independence between categorical variables is commonly evaluated with a chi-squared test.

B

Incorrect. Missingness mechanisms require missing-data analysis, not a basic t-test.

C

Incorrect. AUC evaluates binary classifier ranking performance, not mean differences.