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
[{'content': 'Standard detion is a measure of: \nSelect and explain. \nA. Chance, B. Central tendency, C. Detion from mean value, D. None', 'role': 'user'}, {'content': "Answer: C \nExplanation: The standard detion is the positive square root of variance and is used to measure the detion from the mean value. It gives the extent of spread of dispersion. Thus in simpler terms, the dispersion of values about the mean, is directly propoional to the standard detion. Ref: Fundamental Statistics for The Behavioral Sciences By David C. Howell, Pages 88-90; Park's Textbook of Social and Preventive Medicine, 19th Edition, Page 701", 'role': 'assistant'}]