A researcher compares mean serum creatinine levels between vegetarian and non-vegetarian adults, assuming normal distribution and equal variances. Which assumption is REQUIRED for the independent samples t-test in this scenario?
- A The dependent variable is normally distributed within each group ✓
- B The two populations have equal medians
- C The sample sizes must be at least 50 in each group
- D The dependent variable is measured on an ordinal scale
Correct answer: A. The dependent variable is normally distributed within each group
Explanation
The independent samples t-test requires the dependent variable to be approximately normally distributed within each group, along with homogeneity of variances and independence of observations. Equal medians would mean no difference exists. Large sample sizes are not required. Ordinal scale data would need a non-parametric test.
Reference: Mahajan's Methods in Biostatistics, 9th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.