Normal Dist. and MAD

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 does the Mean Absolute Deviation (MAD) measure?

Back

MAD measures the average distance between each data point and the mean of the data set.

Front

What is the empirical rule in relation to normal distribution?

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

How do you calculate the Mean Absolute Deviation (MAD)?

Back

1. Find the mean of the data set. 2. Subtract the mean from each data point and take the absolute value. 3. Find the average of those absolute values.

Front

What is the significance of the standard deviation in a normal distribution?

Back

Standard deviation measures the dispersion of data points from the mean; a smaller standard deviation indicates that data points are closer to the mean.

Front

If the mean is 65 inches and the standard deviation is 3 inches, what is the range for the first standard deviation?

Back

The range for the first standard deviation is from 62 inches to 68 inches.

Front

What percent of data falls between the first and second standard deviations in a normal distribution?

Back

Approximately 95% of the data falls between the first and second standard deviations.

Front

In a normal distribution, what does the area under the curve represent?

Back

The area under the curve represents the total probability of all outcomes, which equals 1.

Front

What is the z-score in a normal distribution?

Back

The z-score indicates how many standard deviations an element is from the mean.

Front

How do you find the z-score?

Back

Z-score = (X - mean) / standard deviation, where X is the value.