Unit 5 Review

Front

What is a z-score?

Back

A z-score indicates how many standard deviations an element is from the mean. It is calculated as (X - μ) / σ, where X is the value, μ is the mean, and σ is the standard deviation.

Front

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

Back

To calculate the z-score, use 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 negative z-score indicate?

Back

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

Front

What does a positive z-score indicate?

Back

A positive z-score indicates that the value is above 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 mean of a normal distribution?

Back

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

Front

What is the standard deviation in a normal distribution?

Back

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

Front

How do you find the proportion of data above a certain z-score?

Back

To find the proportion of data above a certain z-score, use the standard normal distribution table or a calculator to find the area to the left of the z-score and subtract it from 1.

Front

What is the significance of the top 2% in a normal distribution?

Back

The top 2% of a normal distribution corresponds to a z-score that indicates the threshold for the highest IQ scores, qualifying for organizations like Mensa.

Front

How do you estimate the number of items within a certain range in a normal distribution?

Back

To estimate the number of items within a certain range, calculate the z-scores for the endpoints of the range, find the corresponding areas under the normal curve, and multiply by the total number of items.