Measures of Central Tendency

Standard Deviation

A measure of how spread out numbers are.

Outlier

A number in a set of data that is much larger or smaller than most of the other numbers in the set.

Data Set

A set of numbers that are related in some way.

Lower Quartile

A value is the median of the lower half of the data.

Upper Quartile

A value is the median of the upper half of the data.

Interquartile Range

A value that is the difference between the upper quartile value and the lower quartile value.

Measures of Central Tendency

An average; a single value that is used to represent a collection of data. Three commonly used types of averages are mode, median, and mean.

Variance

The average of the squared differences from the Mean.

Normal Distribution

A function that represents the distribution of many random variables as a symmetrical bell-shaped graph.

Box and Whisker Plot

A graphic way to display the median, quartiles, and extremes of a data set on a number line to show the distribution of the data.

Range

The difference between the greatest number and the least number in a set of numbers.

Median

The middle number of a set of numbers when the numbers are arranged from least to greatest, or the mean of two middle numbers when the set has two middle numbers.

Mode

The mode of a set of numbers is the one that occurs most often.

Statistics

The science of collecting, organizing, representing, and interpreting data.

Mean

The sum of a set of numbers divided by the number of elements in the set. (A type of average)