Calculating z-scores

Front

What is a z-score?

Back

A z-score indicates how many standard deviations an element is from the mean of a dataset.

Front

How do you calculate a z-score?

Back

Z-score = (X - μ) / σ, where X is the value, μ is the mean, and σ is the standard deviation.

Front

If the mean score is 91% and the standard deviation is 7, what is the z-score for a score of 77%?

Back

-2

Front

Given a mean of 21 and a standard deviation of 1.3, what is the z-score for a score of 22?

Back

0.77

Front

What does a negative z-score indicate?

Back

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

Front

What does a positive z-score indicate?

Back

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

Front

If the mean is 27 and the standard deviation is 1.4, what is the z-score for a score of 11?

Back

-11.43

Front

Calculate the z-score for μ = 70, σ = 8, and X = 50.

Back

-2.5

Front

If the mean is 40 and the standard deviation is 1.4, what is the z-score for a score of 42?

Back

1.43

Front

What is the significance of a z-score of 0?

Back

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