AP Stats Chapter 2 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 using the formula: z = (x - μ) / σ.

Front

How do you calculate a z-score?

Back

To calculate a z-score, subtract the mean (μ) from the value (x) and then divide by the standard deviation (σ): z = (x - μ) / σ.

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 means that the values tend to be close to the mean.

Front

What does it mean to find a cutoff score for a certain percentile?

Back

Finding a cutoff score for a certain percentile means determining the score below which a given percentage of scores fall.

Front

How do you find the cutoff score for the bottom 35%?

Back

To find the cutoff score for the bottom 35%, you can use the z-score corresponding to the 35th percentile and then convert it back to the original score using the mean and standard deviation.

Front

What is the probability of a value falling within a certain range?

Back

The probability of a value falling within a certain range can be found using the z-scores for the endpoints of the range and looking up the corresponding probabilities in the standard normal distribution table.

Front

What is the significance of the top 10% in a data set?

Back

The top 10% refers to the highest scores in a data set, and finding the cutoff score for this percentile helps identify the threshold for high performance.

Front

How do you interpret a z-score of -1.2?

Back

A z-score of -1.2 indicates that the value is 1.2 standard deviations below the mean.

Front

What does a z-score of 2.38 indicate?

Back

A z-score of 2.38 indicates that the value is 2.38 standard deviations above the mean.