Unit 6 CC 3: Z-scores and Confidence Intervals

Front

What is a Z-score?

Back

Front

How do you calculate a Z-score?

Back

Front

What does a Z-score of 0 indicate?

Back

A Z-score of 0 indicates that the score is exactly at the mean of the dataset.

Front

What is the purpose of a Z-table?

Back

A Z-table provides the area (or probability) to the left of a given Z-score in a standard normal distribution.

Front

How do you find the area between two Z-scores?

Back

To find the area between two Z-scores, look up each Z-score in the Z-table to find the corresponding probabilities, then subtract the smaller probability from the larger one.

Front

What is a confidence interval?

Back

A confidence interval is a range of values, derived from sample statistics, that is likely to contain the value of an unknown population parameter.

Front

What happens to the confidence interval as confidence level increases?

Back

As the confidence level increases, the width of the confidence interval also increases, meaning you become more confident that the interval contains the true parameter.

Front

What is the relationship between sample size and confidence interval width?

Back

As the sample size increases, the width of the confidence interval decreases, leading to a more precise estimate of the population parameter.

Front

True or False: A larger sample size always guarantees a smaller confidence interval.

Back

True. A larger sample size generally leads to a smaller standard error, which results in a narrower confidence interval.

Front

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

Back

A negative Z-score indicates that the score is below the mean of the dataset.