This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Biostatistics, Subject name: Social & Preventive Medicine
[{'content': 'A study generated a normal distribution with a mean value as 200 and standard deviation of 20. 68% of area will fall between \nSelect and explain. \nA. 180-220, B. 160-240, C. 190-210, D. 150-250', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Normal curve (De Moivrre and Gauss)* Bell shaped, bilaterally symmetrical infinitely large number of observations* Area of the curve is 1* Mean median and mode all coincide which is 0* Standard deviation and variance- 1* Mean +- I SD = 68 % area* Mean +- 2 SD = 95 % area* Mean +- 3 SD = 99% area', 'role': 'assistant'}]