DA0-002 Data Analysis Practice Question
A data analyst wants to test if the proportion of customers who prefer Product A over Product B is different from 50%. She surveys 200 customers and finds that 120 prefer Product A. Which statistical test should she use?
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
✓
One-sample z-test for proportions
A one-sample z-test for proportions compares a sample proportion to a hypothesized population proportion. Here, the null is p=0.5. A chi-square test for goodness-of-fit could also be used, but the z-test is standard for a single proportion.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Chi-square test of independence
Why it's wrong here
For testing independence between two categorical variables.
- ✓
One-sample z-test for proportions
Why this is correct
Correct for testing a single proportion against a hypothesized value.
- ✗
ANOVA
Why it's wrong here
For comparing means of three or more groups.
- ✗
Two-sample t-test
Why it's wrong here
For comparing means of two groups.
Go deeper
Related to this question
About these practice questions
One of 986 original DA0-002 practice questions on Courseiva, each with a full explanation and wrong-answer analysis — not exam dumps or protected exam content. Learn why practice questions differ from exam dumps →
JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
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.