Z-Scores and Normal Distribution

Front

What is a Z-score?

Back

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

Front

What is the formula for finding Z-scores?

Back

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

What is the mean in a normal distribution?

Back

The mean is the average of all data points in a normal distribution.

Front

What is the standard deviation in a normal distribution?

Back

The standard deviation measures the dispersion or spread of the data points around the mean.

Front

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

Back

Approximately 68% of the data falls within one standard deviation of the mean.

Front

What percentage of data falls within two standard deviations of the mean in a normal distribution?

Back

Approximately 95% of the data falls within two standard deviations of the mean.

Front

What percentage of data falls within three standard deviations of the mean in a normal distribution?

Back

Approximately 99.7% of the data falls within three standard deviations of the mean.

Front

How do you find the probability of a value being above a certain Z-score?

Back

Use the Z-table to find the area to the left of the Z-score and subtract it from 1.