Standard Deviation Table Negative. Standard normal cumulative probability table cumulative probabilities for negative z values are shown in the following table. Because the curve is symmetrical the same table can be used for values going either direction so a negative 0 45 also has an area of 0 1736.
Z is negative when the raw score is below the mean positive when above. It is a value below the mean for the group of values. For george s example we need to use the 2nd table as his test result corresponds to a positive z score of 0 67.
To conclude the smallest possible value standard deviation can reach is zero.
If a z score calculation yields a negative standardized score refer to the 1st table when positive used the 2nd table. For george s example we need to use the 2nd table as his test result corresponds to a positive z score of 0 67. Why standard deviation can t be negative mathematically. To conclude the smallest possible value standard deviation can reach is zero.
