I am confused about the answer that is mentioned for this question.

Norm-referenced developmental and motor tests offer a variety of score outputs to interpret a child’s performance on the test. Which statistic below is a standard score used to express a score deviation from a mean of 100 and is often associated with a score classification?
a. T-score
b. Age equivalent score
c. Z-score
d. Percentile score

Z score is the answer but I thought Z score usually had a mean of 0 with a standard deviation of 1 and that the deviation quotient had a mean of 100 with a standard deviation of 15. I understand T score is not the answer it has a mean of 50 and a standard deviation of 10. Just looking for clarification as most tables of standard scores I have been looking at list the above values. Thank you!

Hi Katelin,
Good catch, and I apologize for the confusion. This was a typo that carried through the question.

With a correct answer of “Z-score,” the explanation should be: A Z-score is a standard score computed by subtracting a child’s score from the test mean score and dividing by the test standard deviation; it is typically based on a mean of 0 (zero), is expressed as standard deviation from the mean, and can be positive or negative. A T-score is derived from the Z-score, based on a mean of 50, and always a positive value. Z-scores and T-scores are often used by test developers to determine cut offs for classifications such as “average,” “below average,” etc. A percentile score indicates the number of children of the same age expected to score lower than the subject child. An age-equivalent score reflects the mean raw score on a test obtained by a group of children in the normative sample at that specific age.

The question should have read: Norm-referenced developmental and motor tests offer a variety of score outputs to interpret a child’s performance on the test. Which statistic below is a standard score used to express a score deviation from a mean of zero and is often associated with a score classification?