In a study of 200 antenatal women, the correlation coefficient between maternal age and birth weight is found to be r = -0.82 with p < 0.001. Which interpretation is CORRECT?
- A Older mothers tend to have heavier babies, and the association explains 82% of the variation
- B Increasing age causes a decrease in birth weight
- C Older mothers tend to have lighter babies, with a strong inverse linear association ✓
- D There is no meaningful association since the coefficient is negative
Correct answer: C. Older mothers tend to have lighter babies, with a strong inverse linear association
Explanation
A negative r close to 1 indicates a strong inverse linear relationship, meaning higher maternal age tends to accompany lower birth weight. Option B overstates correlation as causation, which no observational correlation can establish, and option A misreads the sign and confuses r with the coefficient of determination, which would be r squared or about 0.67 here.
Reference: Park's Textbook of Preventive and Social Medicine, 27th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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