AP Stats Chapter 2

Front

What is a percentile?

Back

A percentile is a measure used in statistics indicating the value below which a given percentage of observations fall. For example, the 64th percentile means that 64% of the data points are below that value.

Front

What does it mean if a score is at the 64th percentile?

Back

It means that the score is higher than 64% of the scores in the dataset.

Front

Define quartiles in statistics.

Back

Quartiles are values that divide a dataset into four equal parts. The first quartile (Q1) is the 25th percentile, the second quartile (Q2) is the median (50th percentile), and the third quartile (Q3) is the 75th percentile.

Front

What is the interquartile range (IQR)?

Back

The interquartile range (IQR) is the difference between the third quartile (Q3) and the first quartile (Q1). It measures the spread of the middle 50% of the data.

Front

How do you find the median of a dataset?

Back

To find the median, arrange the data in ascending order and locate the middle value. If there is an even number of observations, the median is the average of the two middle values.

Front

What is the relationship between percentiles and quartiles?

Back

Quartiles are specific percentiles: Q1 is the 25th percentile, Q2 is the 50th percentile (median), and Q3 is the 75th percentile.

Front

What does it mean if a score is between the median and the third quartile?

Back

It indicates that the score is higher than the median but lower than the value at the 75th percentile, meaning it is in the upper half of the data but not in the top 25%.

Front

Explain the concept of the mean in statistics.

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 a box plot?

Back

A box plot is a graphical representation of a dataset that shows the median, quartiles, and potential outliers. It provides a visual summary of the distribution.

Front

Define outlier in statistics.

Back

An outlier is a data point that differs significantly from other observations in a dataset. It may indicate variability in the measurement or may be due to experimental error.