CompTIA Data+ (DA0-002)Data AnalysisMedium
A data analyst is evaluating the effectiveness of a new customer loyalty program. They want to determine if there is a statistically significant difference in the average purchase value of customers enrolled in the program compared to those not enrolled. The purchase values are not normally distributed, and the sample sizes are relatively small. Which statistical test is most appropriate for this analysis?
- AANOVA
- BPearson Correlation Coefficient
- CMann-Whitney U Test
- DIndependent Samples t-test
Show answer & explanationAnswer & explanation
Correct answer: C. Mann-Whitney U Test
The Mann-Whitney U Test is a non-parametric test used to compare two independent groups when the data is not normally distributed or when sample sizes are small. Given the scenario, it is the most appropriate choice.
Why the other options are wrong
- A. ANOVA is used for comparing three or more groups, not two, and assumes normality.
- B. Pearson Correlation Coefficient measures the linear relationship between two variables, not the difference between two groups.
- D. The Independent Samples t-test assumes normality and is less robust to non-normal data with small sample sizes.
Mann-Whitney U Test
A non-parametric statistical test used to compare two independent groups to determine if they come from the same population, often used when data is not normally distributed or sample sizes are small.
- Non-parametric alternative to the independent samples t-test.
- Compares the medians of two independent groups.
- Does not assume normal distribution of data.
Memory trick: Non-normal data, two groups? U-turn to Mann-Whitney!