DA0-002 Data Analysis Practice Question
A marketing team runs an A/B test on email subject lines. The p-value is 0.03 with α = 0.05. Which of the following is the correct interpretation?
⚠ Common exam trap
DA0-002 often tests the interpretation of p-values, and candidates frequently misinterpret the p-value as the probability that the null hypothesis is true or confuse significance with practical importance.
Answer choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Reject the null hypothesis; there is a statistically significant difference.
With a p-value of 0.03 and α = 0.05, the p-value is less than the significance level, so we reject the null hypothesis. This indicates a statistically significant difference at the 95% confidence level. The p-value is not the probability that the null hypothesis is true.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
The result is not statistically significant at the 95% confidence level.
Why it's wrong here
A p-value of 0.03 falls below α = 0.05, so the null hypothesis is rejected and the result is statistically significant. It tempts because 0.03 is a small number, but significance depends on comparison with α, not magnitude alone.
- ✗
The probability that the null hypothesis is true is 3%.
Why it's wrong here
A p-value is the probability of observing data at least this extreme assuming the null hypothesis is true, not the probability that the null itself is true. It tempts because people intuitively invert the conditional, and a Bayesian posterior could legitimately express such a probability.
- ✗
Fail to reject the null hypothesis; no significant difference.
Why it's wrong here
With p = 0.03 below α = 0.05, the null hypothesis is rejected, indicating a statistically significant difference. Failing to reject applies when p exceeds α; the temptation is treating a small p-value as insufficient evidence rather than the threshold breach it represents.
- ✓
Reject the null hypothesis; there is a statistically significant difference.
Why this is correct
With α = 0.05, a p-value of 0.03 falls below the significance threshold, so the null hypothesis is rejected. The result is statistically significant, meaning the observed difference in subject-line performance is unlikely to have arisen from chance alone.
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Written and reviewed by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
Last reviewed September 2026 · checked against the official CompTIA exam blueprint
This DA0-002 practice question is part of Courseiva's free CompTIA 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 DA0-002 exam.