hey even cie book says the same....if the probability obtained is greater than 0.05 (5%)...which includes 0.1 ,0.2..this means it is not significant(due to chance) and if we get a probability that is less than 0.05 it means its significant(not due to chance)....this the the chi square test....if its the t-test....if the value obtained is greater than the critical value it is significant.......