Front

What is the mean in a normal distribution?

Back

The mean is the average value of the data set and is the center of the normal distribution curve.

Front

What does the standard deviation represent in a normal distribution?

Back

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

Front

How do you calculate the z-score for a given value?

Back

The z-score is calculated using the formula: z = (X - μ) / σ, where X is the value, μ is the mean, and σ is the standard deviation.

Front

What does a z-score of -1.25 indicate about a data point?

Back

A z-score of -1.25 indicates that the data point is 1.25 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 one standard deviation of the mean, 95% within two standard deviations, and 99.7% within three standard deviations.

Front

What is the purpose of the z-table?

Back

The z-table provides the percentage of data points that fall below a given z-score in a standard normal distribution.

Front

What percent of values are less than a z-score of 0?

Back

50% of values are less than a z-score of 0 in a standard normal distribution.

Front

If the mean is 64.5 and the standard deviation is 2.5, what percent of young women have heights between 62 and 72 inches?

Back

About 84% of young women have heights between 62 and 72 inches.

Front

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

Back

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

Front

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

Back

A negative z-score indicates that the data point is below the mean.