Calculating Z-Scores

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. It indicates how many standard deviations an element is from the mean.

Front

How do you calculate the Z-score for a population?

Back

The formula for calculating the Z-score for a population is: @@z = rac{x - u}{ heta}@@ where x is the value, ν is the mean, and θ is the standard deviation.

Tags

CCSS.HSS.ID.A.4

Front

What does a Z-score of -2.00 indicate?

Back

A Z-score of -2.00 indicates that the value is 2 standard deviations below the mean.

Front

If the mean is 21 and the standard deviation is 1.3, what is the Z-score for x = 22?

Back

Front

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

Back

A Z-score of 0 indicates that the value is exactly at the mean.

Front

How do you interpret a positive Z-score?

Back

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

Front

How do you interpret a negative Z-score?

Back

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

Front

What is the Z-score for a value that is 3 standard deviations above the mean?

Back

The Z-score for a value that is 3 standard deviations above the mean is +3.00.

Front

What is the Z-score for a value that is 1.5 standard deviations below the mean?

Back

The Z-score for a value that is 1.5 standard deviations below the mean is -1.50.

Front

If the mean is 22 and the standard deviation is 3.1, what is the Z-score for x = 29?

Back

Tags

CCSS.HSS.ID.A.4