Flashcard Z-Scores

Front

What is a z-score?

Back

A z-score indicates how many standard deviations a data point is from the mean of a data set.

Front

How do you calculate a z-score?

Back

Front

What does a positive z-score indicate?

Back

A positive z-score indicates that the data point is above the mean.

Front

What does a negative z-score indicate?

Back

A negative z-score indicates that the data point is below the mean.

Front

What is the significance of the 75th percentile in relation to z-scores?

Back

The 75th percentile corresponds to a z-score of approximately 0.67, meaning 75% of the data points are below this value.

Front

If a student's z-score is +2.50, what does it imply about their performance?

Back

It implies that the student scored 2.5 standard deviations above the average.

Front

What is the mean GPA of a local high school if the highest 2.5% of students have a GPA of 4.1 or higher?

Back

The mean GPA is 2.9, with a standard deviation of 0.6.

Front

How do you interpret a z-score of 0?

Back

A z-score of 0 indicates that the data point is exactly at the mean.

Front

What is the z-score for a data point of 265 in a dataset with a mean of 290 and a standard deviation of 20?

Back

Front

What does it mean if a z-score is greater than 3?

Back

A z-score greater than 3 indicates that the data point is significantly higher than the mean, often considered an outlier.