Which measure of central tendency can be used for nominal data such as blood group distribution in a population?
- A Mean
- B Mode ✓
- C Median
- D Geometric mean
Correct answer: B. Mode
Explanation
The mode is the most frequently occurring value and requires no ordering or numerical computation, so it applies to nominal categories like blood groups. The mean and geometric mean require interval scale data, and the median requires at least ordinal data where values can be ranked. Blood group O being commonest in a community is a statement about the mode. This makes the mode the only measure valid for purely qualitative nominal variables.
Reference: Park's Textbook of Preventive and Social Medicine, 27th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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