In a study comparing mean blood glucose values between diabetics and controls using an independent samples t-test, the p-value is 0.03. The researcher then discovers that the data violates the normality assumption. Which non-parametric test is the most appropriate alternative?
- A Mann-Whitney U test ✓
- B Wilcoxon signed-rank test
- C Kruskal-Wallis test
- D Friedman test
Correct answer: A. Mann-Whitney U test
Explanation
The Mann-Whitney U test is the non-parametric equivalent of the independent samples t-test and is used when comparing two independent groups with non-normally distributed continuous or ordinal data. The Wilcoxon signed-rank test is for paired data, Kruskal-Wallis for three or more independent groups, and Friedman for repeated measures across groups.
Reference: Park's Textbook of Preventive and Social Medicine, 27th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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