In a normally distributed population with mean fasting glucose of 90 mg/dL and standard deviation of 10 mg/dL, approximately what percentage of individuals have values between 80 and 100 mg/dL?
- A 99.7%
- B 95%
- C 68% ✓
- D 34%
Correct answer: C. 68%
Explanation
80 to 100 mg/dL spans mean plus or minus 1 SD (90 plus/minus 10). By the empirical rule, approximately 68% of values lie within 1 SD of the mean in a normal distribution. Option D is half of that (one tail only). Option B corresponds to mean plus/minus 2 SD. Option A is mean plus/minus 3 SD. The 68-95-99.7 rule is a fundamental concept tested directly.
Reference: Basic and Clinical Biostatistics, 4th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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