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 data set.

Front

How do you calculate a z-score?

Back

Z-score = (x - mean) / standard deviation

Front

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

Back

1.43

Front

What does a positive z-score indicate?

Back

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

Front

What does a negative z-score indicate?

Back

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

Front

If the mean is 22.8 and the standard deviation is 7, what is the z-score for x = 20?

Back

-0.4

Front

What is the z-score for x = 50 if the mean is 45 and the standard deviation is 2.1?

Back

2.38

Front

If the mean is 38 and the standard deviation is 1.2, what is the z-score for x = 42?

Back

3.33

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.

Front

What is the formula for the mean?

Back

Mean = (Sum of all values) / (Number of values)