AP Statistics Unit 1: Types of Variables, Data and Display

Descriptive Statistics

statistical procedures used to describe characteristics and responses of groups of subjects

Inferential Statistics

numerical methods used to determine whether research data support a hypothesis or whether results were due to chance

Numerical Statistics

represent measurements where the actual numbers are important (height and weight). Might include MEASURES OF CENTER and MEASURES OF SPREAD

Quantitative Statistics

Numerical based, incorporates averages (mean, median, mode) to describing data.

Categorical Statistics

individuals in groups (gender or political affiliation) that are summarized using the # of indivs in each group = FREQUENCY or percent of indivs = RELATIVE FREQUENCY

Qualitative

relating to or involving comparisons based on qualities

Population

a group of organisms of the same species populating a given area

Sample

items selected at random from a population and used to test hypotheses about the population

Variable

a quantity that can assume any of a set of values

Discrete

unconnected; separate; distinct

Continuous

of a function or curve. non stop.

Skewed Right

The data is stretched to the right. Most of your data is on the left and your tail is to the right. (Negatively Skewed)

Skewed Left

The data is stretched to the left. Most of your data is on the right. The tail is to the left. (Positively Skewed)

Symmetric

having similarity in size, shape, and relative position of corresponding parts.

Bell-shaped

symmetric

Unimodal

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

Bimodal

distributions with two modes

Multi-modal

Distribution with mutliple modes

Variation

(biology) an organism that has characteristics resulting from chromosomal alteration.

Quartile

(statistics) any of three points that divide an ordered distribution into four parts each containing one quarter of the scores.

Range

the limits of the values a function can take

Standard Deviation

a measure of variability that describes an average distance of every score from the mean

Outlier

an extreme deviation from the mean

Dotplot

A one dimensional plot of a quantitative data set where each value in the data set is represented by a dot above its corresponding location on the x axis.

Boxplot

displays the 5-number summary as a central box with whiskers that extend to the non-outlying data values

Steam and Leaf Plot

a system used to condense a set of data where the gratest place value of the data forms the stem and the next greatest place value forms the leaves

Histogram

A graph of vertical bars representing the frequency distribution of a set of data.

Timeplot

displays data that change over time

Scatterplot

A graphed cluster of dots, each of which represents the values of two variables

Bar Graph

a chart with bars whose lengths are proportional to quantities

Pie Chart

a circular chart divided into triangular areas proportional to the percentages of the whole

Context

discourse that surrounds a language unit and helps to determine its interpretation