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': 'All are true about P-value except \nSelect and explain. \nA. Is the probability of committing Type-I error, B. When P-value is less than a, the result is statistically significant, C. Is the chance that the presence of difference is concluded when actually there is none, D. Is equal to 1-b', 'role': 'user'}, {'content': 'Answer: D \nExplanation: • ‘Type I error is usually fixed in advance’ by the choice of level of significance employed in the test\n• Type I error is more serious than Type II error\n• Power of a test: 1 – b\n– Is probability of rejecting a Null hypothesis when a predetermined clinically significant difference is indeed present\n– Power can be increased by increasing the no. of subjects in a trial', 'role': 'assistant'}]