All are true about P-value except:: (A) Is the probability of committing Type -I error, (B) Is equal to 1-beta, (C) Is the chance that the presence of difference is concluded when actually there is none, (D) When P- value is less than a, the result is statistically significant
Answer is B. Type I error is usually fixed in advance by the choice of level of significant employed in the test Type I error is more serious than Type II error Power of a test: 1-b -Is probability of rejecting a Null hypothesis when a predetermined clinically significant difference is indeed present -Power can be increased by increasing the no. of subjects in a trial There is no mathematical relationship between a and b.