<prompt> All are true about P-value exceptIs the probability of committing Type-I errorWhen P-value is less than a, the result is statistically significantIs the chance that the presence of difference is concluded when actually there is noneIs equal to 1-b  <response>: Type I error is usually fixed in advance by the choice of level of significance 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 