Standard Normal Distribution Practice

Front

What is a standard normal distribution?

Back

A standard normal distribution is a normal distribution with a mean of 0 and a standard deviation of 1.

Front

What is a z-score?

Back

A z-score indicates how many standard deviations a data point is from the mean of the data set.

Front

How do you calculate a z-score?

Back

Front

What does a z-score of -2 indicate?

Back

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

Front

What is the empirical rule in statistics?

Back

The empirical rule states that for a normal distribution, approximately 68% of the data falls within 1 standard deviation of the mean, 95% within 2 standard deviations, and 99.7% within 3 standard deviations.

Front

If a data set has a mean of 300 and a standard deviation of 40, what value corresponds to a z-score of -2?

Back

220.

Front

What is the purpose of z-scores?

Back

Z-scores describe the exact location of a score within a distribution.

Front

What percentage of data falls within one standard deviation of the mean in a normal distribution?

Back

Approximately 68%.

Front

If a data set has a mean of 20 and a standard deviation of 3, what is the z-score for 23?

Back

Front

What does it mean if a z-score is positive?

Back

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