Normal Distribution

Front

What is a normal distribution?

Back

A normal distribution is a probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean.

Front

What shape is a normal distribution curve?

Back

Bell curve.

Front

According to the empirical rule, what percentage of data falls within 1 standard deviation of the mean?

Back

68%.

Front

According to the empirical rule, what percentage of data falls within 2 standard deviations of the mean?

Back

95%.

Front

According to the empirical rule, what percentage of data falls within 3 standard deviations of the mean?

Back

99.7%.

Front

What does it mean if a data point is one standard deviation above the mean in a normal distribution?

Back

It means the data point is higher than approximately 84% of the data.

Front

What is the mean in a normal distribution?

Back

The mean is the average of all data points and is located at the center of the distribution.

Front

What is the standard deviation in a normal distribution?

Back

The standard deviation measures the amount of variation or dispersion of a set of values.

Front

If the mean is 75 and the standard deviation is 7, what is the z-score for a score of 82?

Back

The z-score is (82 - 75) / 7 = 1.

Front

What does a z-score represent in a normal distribution?

Back

A z-score represents the number of standard deviations a data point is from the mean.