A negative z-score indicates a value the average. However, a negative z-score indicates a value closer to the mean, thus a better performance in comparison.

A z-score tells how many standard deviations a value is from the mean. A negative z-score means the value is below—and therefore smaller than—the average, so “smaller” is correct. The size of the negative z-score, not just its negative sign, determines how close it is to the mean.

AI-written and checked against the verified answer.