Final Review U1 Inferential Statististics

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, about 95% falls within two standard deviations, and about 99.7% falls within three standard deviations.

Front

Define Z-score.

Back

A Z-score is a statistical measurement that describes a value's relationship to the mean of a group of values. It is calculated by subtracting the mean from the value and then dividing by the standard deviation.

Front

What does a Z-score of 0.77 indicate?

Back

A Z-score of 0.77 indicates that the value is 0.77 standard deviations above the mean.

Front

What is a primary source in research?

Back

A primary source is an original document or firsthand account that has not been altered or interpreted by others, such as interviews, surveys, or original research data.

Front

How do you calculate the probability of a range in a normal distribution?

Back

To calculate the probability of a range in a normal distribution, you can use the Z-scores for the endpoints of the range and refer to the standard normal distribution table.

Front

What is the mean in a data set?

Back

The mean is the average of a set of numbers, calculated by adding all the values together and dividing by the number of values.

Front

What is standard deviation?

Back

Standard deviation is a measure of the amount of variation or dispersion in a set of values. A low standard deviation indicates that the values tend to be close to the mean, while a high standard deviation indicates that the values are spread out over a wider range.

Front

If the mean is 30 and the standard deviation is 5, what is the value at one standard deviation above the mean?

Back

35 (30 + 5).

Front

What percentage of data falls below the mean in a normal distribution?

Back

50% of the data falls below the mean in a normal distribution.

Front

What is the formula for calculating a Z-score?

Back

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