Z-Score Flashcard

Front

What is a z-score?

Back

A z-score is a statistical measurement that describes a value's relationship to the mean of a group of values, expressed in terms of standard deviations from the mean.

Front

How do you calculate a z-score?

Back

Z-score = (Data Value - Mean) / Standard Deviation

Front

What does a z-score of 0 indicate?

Back

A z-score of 0 indicates that the data value is exactly equal to the mean.

Front

What does a positive z-score indicate?

Back

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

Front

What does a negative z-score indicate?

Back

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

Front

If the mean is 50 and the standard deviation is 10, what is the z-score for a data value of 60?

Back

Z-score = (60 - 50) / 10 = 1.0

Front

If the mean is 30 and the standard deviation is 5, what is the z-score for a data value of 25?

Back

Z-score = (25 - 30) / 5 = -1.0

Front

What does it mean if a z-score is greater than 2?

Back

A z-score greater than 2 indicates that the data value is more than 2 standard deviations above the mean.

Front

What does it mean if a z-score is less than -2?

Back

A z-score less than -2 indicates that the data value is more than 2 standard deviations below the mean.

Front

How can z-scores be used in standardizing data?

Back

Z-scores can be used to standardize data by converting different data sets to a common scale, allowing for comparison.