AP Statistics Distributions

Variable

Any characteristic whose value changes

Categorical/Qualitative

Data about basic characteristics which are not measured by numbers

Numerical/Quantitative

Data that can be measured with numerical values

Discrete Variables

Numeric values that are countable and limited

Continuous Variables

A numeric value that can take on any value in a range (measured ex. weight)

The name for 1, 2 and multiple variable distributions

Univariate, bivariate, and multivariate distributions

Symmetrical

Data where both sides are the same size and shape

Uniform

Every class has an equal number

Skewed

One side is longer than the other side (skewed on the side the long tail is)

Bimodal

Two humps in the data

Center

The middle of the data measured by mean, median, mode

Spread

Measured by standard deviation, range, IQR, variance

Shape

Symmetrical, skewed, uniform, unimodal or bimodal

How to describe a distribution

Shape, spread, center, outliers

Median

The middle point of the data when arranged in numerical order

Mean

All the data values added together and divided by the number of data values

Mode

The data value that occurs most in the data

Range

Max-min

IQR

Q3-Q1

Standard Deviation

The average number of variations from the mean

Variance

Standard Deviation²