lly large samples, mean can 29. Large Sample and a Small Difference It has been said that even very small differences between the sample mean and the claimed population appear to be significant, but in reality they are not significant. Test this statement using the claim that the mean IQ score of adults is 100, given the following sample data: n = 1,000,000, x=100.05, s = 15. Based on this sample, is the difference between = 100.05 and the claimed mean of 100 statistically significant? Does that difference have practical significance?