AP Stats 1.3, 2.1, 2.2 Vocab

TERM	DEFINITION
Bar Graph	A data visualization tool that compares data across different categories or groups. It uses bars to present numeric values for levels of data categories, which can extend horizontally or vertically.
Pie Chart	A pie chart is a circular statistical graphic which is divided into slices to illustrate numerical proportion. In a pie chart, the arc length of each slice is proportional to the quantity it represents.
Two-way Table	A table that summarizes data on the relationship between two categorical variables for some group of individuals.
Marginal Relative Frequency	The percent or proportion of individuals that have a specific value for one categorical variable.
Joint Relative Frequency	The percent or proportion of individuals that have a specific value for one categorical variable and a specific value for another categorical variable.
Conditional Relative Frequency	The percent or proportion of individuals that have a specific value for one categorical variable among individuals who share the same value of another categorical variable (the condition).
Conditional Distribution
Side-by-side bar graph
Segmented bar graph
Mosaic plot
Association	Knowing the value of one variable helps us predict the value of the other.
No association	Knowing the value of one variable does not help us predict the value of the other.

TERMS	DEFINITION
Dotplot
Symmetric
Skewed right	Right side of the graph is much longer than the left side.
Skewed left	Left side of the graph is much longer than the right side.
Unimodal	Single peak
Bimodal	Two distinct clusters and peaks
Approximately symmetric	One peak, and the left and right sides are about the same (think of a hill).
Uniform	Frequencies are about the same for all values.
Stemplot
Histogram	Shows each interval of values as a bar. The heights of the bars show the frequencies or relative frequencies of values in each interval.

Unit 1.3

TERMS	DEFINITIONS
Mean	The average of all the individual values.
Statistic	A number that describes some characteristic of a sample.
Parameter	A number that describes some characteristic of a population.
Resistant	When a statistical measure isn’t resistant to extreme values.
Median	The number that is in the middle of the distribution.
Range	Maximum - minimum
Standard deviation	The typical value distance of the values in a distribution from the mean.
Sample variance
Sample Standard Deviation
Quartiles	Divisions in the distribution.
1st Quartile	The median of the values that are left of the actual median.
3rd Quartile	The median of the values that are right of the actual median.
Interquartile Range (IQR)	Q3 - Q1 = IQR
Outlier	Formulas: Low outliers: Q1 - 1.5 x (Q3-Q1) High outliers: Q3 + 1.5 x (Q3-Q1)
5 number summary	Minimum, Q1, Median, Q3, Maximum
Boxplot

Percentile (pth)

The value with p% of observations less than or equal to it.

Cumulative Relative Frequency Graph

A point corresponding to the percentile of a given value in a distribution of quantitative data. Consecutive points are then connected with a line segment to form the graph.

Standardized score (z-score)

IMPORTANT TO KNOW

z=value - meanstandard deviation or z=x-

TERMS	DEFINITIONS
Density Curve
Mean of a Density Curve	The point at which the curve would balance if made of solid material.
Median of a Density Curve	The equal-areas point, or the point that divides the area under the curve in half. Skewed right - (mean > median) mean is closer to tail. Skewed left - (mean < median) mean is closer to the first end.
Normal distribution	Symmetric density curves, single-peaked, bell-shaped
Normal Curve	Same thing as Normal distribution
Empirical Rule	(68-95-99.7) 68% - 1 standard deviation of the mean. 95% - 2 standard deviations of the mean. 99.7% - 3 standard deviations of the mean.
Standard Normal Distribution	Normal distribution with mean 0 and standard deviation 1.