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 chest physician observed that the distribution of forced expiratory volume (FEV) in 300 smokers had a median value of 2.5 litres with the first and third quailes being 1.5 and 4.5 litres respectively. Based on this data now many persons in the sample ra eexpectable have a FEV between 1.5 and 4.5 litres- \nSelect and explain. \nA. 75, B. 150, C. 225, D. 300', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Here, it&;s given 1st and 3rd quaile, which includes 50% values . Here total is 300. So 50% means 150', 'role': 'assistant'}]