The 2.00 because the standard deviation 2.00 is directly above the mean and correspond to highest of five different likely test scores. A z score or the standard value is the number of standard deviations that a given value x is above or below the mean. A negative z score corresponds to an x value less than the mean. A positive z score corresponds to an x value greater than the mean. The more negative the z score the further the x value is below the mean. The more positive the z score the further the x value is above the mean.