This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Normal Distribution, Skewed Distributions, Subject name: Social & Preventive Medicine
[{'content': '68% values are covered in how many Standard Detions (SD)? \nSelect and explain. \nA. 1 SD, B. 2 SD, C. 3 SD, D. 4 SD', 'role': 'user'}, {'content': "Answer: A \nExplanation: Normal / Gaussian curve:- Is 'bilaterally symmetrical, bell - shaped'. Mean, Median and Mode coincide. (Mean = Median = Mode) Has mean (u) = 0 and SD (s) = 1. 1) Mean +- 1SD (u +- 1s) covers 68% values. 2) Mean +- 2SD (u +- 2s) covers 95% values. 3) Mean +- 3SD (u +- 2s) covers 99% values.", 'role': 'assistant'}]