AP Statistics Unit 1 Vocab

An object described in a set of data (can be people, animals, or things) “nouns”

An object described in a set of data (can be people, animals, or things) “nouns”

Individuals

A characteristic that can take different individuals “adjectives”

Variable

Takes values that are labels, which place each individual into a particular group/category

Categorical Variable

Takes number values that are quantities, counts, or measurements

Quantitative Variable

The distribution of a variable tells us what values the variable takes and how often it takes each value

Distribution

Shows the number of individuals having each value

Frequency Table

Shows the proportion, fraction, or percentage of individuals having each value

Relative Frequency Table

Shows categories as a bar

The heights of the bars show the relative frequencies

Bar Graph

Shows each category as a slice of data, the areas of the slices are proportional to the relative frequencies

Pie Chart

Displays the distribution of 1 categorical variable in each of 2 or more groups

Side-by-Side Bar Graph

A quantitative variable that takes a countable set of possible values with gaps between them on the number line

Discrete Variable

A quantitative variable that can take any value in an interval on the number line

Continuous Variable

Shows each data value as a dot above its location on a number line

Dotplot

The right side of the graph is approximately a mirror image of the left side

Roughly Symmetric

The left side of the graph is much longer than the right side

Skewed Left

The right side of the graph is much longer than the left side

Skewed Right

The relative frequency of each possible value is about the same

Approximately Uniform

Shows each data value separated into two parts: a stem, which consists of the leftmost, and a leaf, consisting of the final digit. The leaves are arranged in increasing order out from the appropriate stems

Stemplot

Shows each interval as a bin. The heights of the bins show the frequencies or relative frequencies of values in each interval

Histogram

The midpoint of a distribution - the number such that about half the observations are smaller and about half are larger

To find it, arrange the data values from smallest to largest

Median

A number that describes some characteristics of a sample

x̄

Statistic

A number that describes some characteristic of a population

μ

Parameter

A statistical measure that is not affected much by extreme data values

Resistant

The average of all the individual data values. To find it, add all the values and divide by the total number of data values

Mean

Distribution of a quantitative data consists of the minimum, first quartile, median, third quartile, and the maximum

5 Number Summary

A visual representation of the 5 number summary

Boxplot

The distance between the first and third quartiles of a distribution

Interquartile Range (IQR)