A standardized score (z-score) of +2.5 signifies what in terms of Parker's academic performance?

A z-score measures how many standard deviations a data point is from the mean of a distribution. A standardized score of +2.5 indicates that Parker's score is 2.5 standard deviations above the mean. This means Parker performed significantly better than the average student in that dataset.

In terms of academic performance, a z-score of +2.5 suggests that Parker's scores are well above average, reflecting a high level of achievement compared to peers. The other options incorrectly interpret the relationship of the z-score to the mean and the standard deviation, neglecting that a positive z-score indicates performance above the average. Thus, the assertion that Parker is 2.5 standard deviations above average is accurate and highlights their strong performance.