Group A children have mean height 100 cm with SD 8 cm. Group B children have mean height 80 cm with SD 6 cm. To compare relative variability of heights between the two groups, the correct statistic is:
- A Standard error of the mean
- B Coefficient of variation ✓
- C Interquartile range
- D Range
Correct answer: B. Coefficient of variation
Explanation
Coefficient of variation equals SD expressed as a percentage of the mean, allowing comparison of dispersion between groups with different means or units. Group A has CV of 8% and Group B has 7.5%, so Group A is relatively more variable despite its larger absolute SD. Standard error measures precision of the mean, not relative spread, and range ignores the central bulk of the data.
Reference: Mahajan's Methods in Biostatistics for Medical Students and Research Workers, 10th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.