This whole area right here is 99.992. If we look at the area of 2.5 standard deviations above and below the mean, let me be careful, this isn't just 2.5, we have to add another digit of precision. This is 2.5, and the next digit of precision is given by this column over here. We have to look all the way up into the second to last column, and we have to add a digit of 8 here. This is 2.58 standard deviations. We have 2.5 over here, and then we get the next digit, 8, from the column. 2.58 standard deviations above and below the standard deviation encompasses a little over 99% of the total probability.