AP Stats Summer Study

Quartiles

Values that divide a data set into four equal parts

Categorical Variable

Take on values that are names or labels

Quantitative Variable

They represent a measurable quantity

Discrete Variables

Assume values that can be counted (cannot take on any value)

Continuous

Can take on any value between its maximum value and its minimum value

Univariate Data

Data with one variable

Bivariate Data

Data with two variables, or pairs of numerical observations

Median

The middle score in a distribution; half the scores are above it and half are below it

Mean

The arithmetic average of a distribution, obtained by adding the scores and then dividing them by the number on scores

Outlier

A data point that diverges greatly from the overall pattern of data

Range

The difference between the highest and lowest scores in a distribution

Variance

Standard deviation squared, a numerical value used to indicate how widely individuals in a group vary

Standard Deviation

The square root of the variance, a numerical value used to indicate how widely individuals in a group vary

Interquartile Range

The difference between the upper quartile and the lower quartile

Unimodal

Having one mode; this is a useful term for describing the shape of a histogram when it’s generally mound-shaped

Bimodal

Two peaks