This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Social & Preventive Medicine
Mean hemoglobin of a group of pregnant females is found to be 10.6 gm/dL with Standard deviation of 2 gm/dL. 5% pregnant females in this group will have their hemoglobin level below 
Select and explain. 
A. 7.31 gm/dL, B. 8.6 gm/dL, C. 6.6 gm/dL, D. 5.0 gm/dL
A: 7.31 gm/dL
Answer: A: 7.31 gm/dL 
Explanation: • Mean + 1SD covers 68% values; So, Hb of 68% pregnant females will lie between 10.6 + 2 gm/dL or between 8.6-12.6
g/dL
- So, 16% will lie below 8.6 gm/dL
• Similarly, Mean + 2SD covers 95% values; So, Hb of 95% pregnant females will lie between 10.6 + 2(2) gm/dL or between 6.6-14.6 gm/dL
- So, 2.5% will lie below 6.6 gm/dL
• So 5% pregnant females will have Hb below 7.31 gm/dL