A study reports haemoglobin values with a standard deviation of 1.5 g/dL and a mean of 12 g/dL, while another study reports fasting glucose with a standard deviation of 30 mg/dL and a mean of 100 mg/dL. To compare relative variability between these two datasets, the appropriate statistic is:
- A Coefficient of variation ✓
- B Standard error of the mean
- C Range
- D Interquartile range
Correct answer: A. Coefficient of variation
Explanation
The coefficient of variation is the standard deviation expressed as a percentage of the mean, giving a unit-free measure of relative dispersion. Here it is 12.5% for haemoglobin and 30% for glucose, showing glucose values are relatively more variable. Standard error measures precision of the mean estimate rather than spread of raw data, and range and interquartile range carry units, making direct comparison across different measurement scales invalid.
Reference: Park's Textbook of Preventive and Social Medicine, 27th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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