Percentiles and Z-Scores Practice

Front

What is a Z-score?

Back

A Z-score indicates how many standard deviations an element is from the mean. It is calculated as (X - μ) / σ, where X is the value, μ is the mean, and σ is the standard deviation.

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

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 a student's score is at the mean, what is their Z-score?

Back

The Z-score would be 0, as the score is equal to the mean.

Front

What is the significance of a Z-score of +2.00?

Back

A Z-score of +2.00 means the score is 2 standard deviations above the mean.

Front

What is the significance of a Z-score of -1.00?

Back

A Z-score of -1.00 means the score is 1 standard deviation below the mean.

Front

How do you interpret Z-scores in comparison?

Back

Higher Z-scores indicate better performance relative to the mean, while lower Z-scores indicate poorer performance.

Front

What is the formula for calculating the Z-score of a test score?

Back

Z = (Test Score - Mean) / Standard Deviation.

Front

If the mean of a dataset is 50 and the standard deviation is 10, what is the Z-score for a value of 70?

Back

Z = (70 - 50) / 10 = +2.00.