In a survey recording the blood group of each participant, which measure of central tendency can be meaningfully calculated?
- A Mode ✓
- B Median
- C Mean
- D Geometric mean
Correct answer: A. Mode
Explanation
Blood group is nominal categorical data: categories have no order and no numerical value, so means and medians cannot be computed. The mode, defined as the most frequently occurring value, is the only measure of central tendency applicable to nominal data. Blood group O is the commonest group in most Indian populations, and stating the modal category is the legitimate summary. This is a favourite examination distinction between scales of measurement.
Reference: Mahajan's Methods in Biostatistics for Medical Students and Research Workers, 10th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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