Question 360:

Asked on August 27, 2008

1

Answer:

No answer provided yet.A negative z-score means the value is below the mean of the sample or population from which it was deived. If a z-score is 0 it means the value is equal to the mean. If a z-score is positive, it means the value is greater than the mean.  For example, given a group of IQ scores with a mean of 100 and standard deviation of 15, if you have a raw score of 75, it is below the mean of 100, so it's z-score would be negative. The z-score would be (75-100)/15 = -1.666. You can see negative z-scores in action by taking a look at the interactive graph of the standard normal curve.