AP Stats 1.3, 2.1, 2.2 Vocab

Bar Graph

A data visualization tool that compares data across different categories or groups using bars to present numeric values.

Pie Chart

A circular statistical graphic divided into slices to illustrate numerical proportion, where the arc length of each slice is proportional to the quantity it represents.

Two-way Table

A table summarizing data on the relationship between two categorical variables for a group of individuals.

Marginal Relative Frequency

The percent or proportion of individuals with a specific value for one categorical variable.

Joint Relative Frequency

The percent or proportion of individuals with a specific value for one categorical variable and a specific value for another.

Conditional Relative Frequency

The percent or proportion of individuals with a specific value for one categorical variable among those sharing the same value of another categorical variable.

Conditional Distribution

The distribution of a variable given a specific condition on another variable.

Side-by-side bar graph

A bar graph that displays two or more sets of data side by side for comparison.

Segmented bar graph

A bar graph that shows the composition of a whole by dividing each bar into segments.

Mosaic plot

A graphical representation of data that displays the relationship between two categorical variables.

Association

A relationship where knowing the value of one variable helps predict the value of another.

No association

A situation where knowing the value of one variable does not help predict the value of another.

Dotplot

A simple data visualization that uses dots to represent individual data points.

Symmetric

A distribution where the left and right sides are mirror images.

Skewed right

A distribution where the right side is much longer than the left side.

Skewed left

A distribution where the left side is much longer than the right side.

Unimodal

A distribution with a single peak.

Bimodal

A distribution with two distinct clusters and peaks.

Approximately symmetric

A distribution with one peak and roughly equal left and right sides.

Uniform

A distribution where frequencies are about the same for all values.

Stemplot

A graphical method for displaying quantitative data, showing the distribution while retaining the original data values.

Histogram

A bar graph that shows the frequency or relative frequency of values in each interval.

Mean

The average of all individual values in a dataset.

Statistic

A number that describes some characteristic of a sample.

Parameter

A number that describes some characteristic of a population.

Resistant

A statistical measure that is not affected by extreme values.

Median

The middle number in a distribution.

Range

The difference between the maximum and minimum values in a dataset.

Standard deviation

A measure of the typical distance of values in a distribution from the mean.

Sample variance

A measure of how much values in a sample differ from the sample mean.

Sample Standard Deviation

The square root of the sample variance.

Quartiles

Divisions in a distribution that split the data into four equal parts.

1st Quartile

The median of the values to the left of the actual median.

3rd Quartile

The median of the values to the right of the actual median.

Interquartile Range (IQR)

The difference between the 3rd and 1st quartiles (Q3 - Q1).

Outlier

A value that lies significantly outside the range of the rest of the data.

5 number summary

A summary that includes the minimum, 1st quartile, median, 3rd quartile, and maximum.

Boxplot

A graphical representation of the 5 number summary.

Percentile (p-th)

The value below which a given percentage of observations fall.

Cumulative Relative Frequency Graph

A graph that shows the cumulative frequency of data points up to a certain value.

Standardized score (z-score)

A measure that describes a value's relation to the mean of a group of values.

Density Curve

A curve that shows the distribution of a continuous random variable.

Mean of a Density Curve

The point at which the curve would balance if made of solid material.

Median of a Density Curve

The point that divides the area under the curve in half.

Skewed right (mean > median)

A distribution where the mean is closer to the tail on the right.

Skewed left (mean < median)

A distribution where the mean is closer to the first end on the left.

Normal distribution

A symmetric, single-peaked, bell-shaped distribution.

Normal Curve

Another term for normal distribution.

Empirical Rule (68-95-99.7)

A rule stating that 68% of data falls within