Probability & Statistics

Probability

A measure of the likelihood that an event will occur.

Counting Principle

If one event can happen M ways and another event can happen N ways then the two events can happen in MN ways.

Tree Diagram

A diagram that shows all of the possible arrangements of objects or outcomes of an event.

Measures of Central Tendency

A single number that can represent a set of numbers. The mean, median, and mode of a set of numbers.

Mean

The sum of a set of numbers divided by how many numbers are in the set.

Median

The MIDDLE NUMBER (or average of two middle numbers) of a group of numbers listed in order.

Mode

The number that occurs the most often in a set of data.

Stem and Leaf Plot

A method of arranging data in increasing or decreasing order.

Box and Whisker Plot

A graphical display that uses a box to represent the middle of a set of data and segments drawn to extremes on both ends.

Lower Extreme

The smallest number in a data set (box & whisker).

Upper Extreme

The largest number in a data set (box & whisker).

Lower Quartile

The median of the lower half of data (box & whisker).

Upper Quartile

The median of the upper half of data (box & whisker).

Interquartile Range

The difference between the upper and lower quartiles.

Second Quartile

The median of the data (box & whisker).

Range

The difference between the upper and lower extremes.

Scatterplot

A graph of a collection of ordered pairs that represent a real life situation.

Positive Correlation

Data points on a scatterplot whose y-coordinates seem to increase as the x-coordinates increase.

Negative Correlation

Data points on a scatterplot whose y-coordinates seem to decrease as the x-coordinates decrease.

No Correlation

Data on a scatterplot for which no pattern exists between the x and y coordinates.

Bar Graph

A graph that organizes a collection of data by horizontal or vertical bars to display how many times each event occurs.

Line Graph

A graph that shows trends over time.

Circle Graph

A graph that shows portions of data collections as part of a circular region.

Histogram

A bar graph in which the bars represent equally spaced intervals of numbers.

Matrix

A rectangular arrangement of numbers into horizontal and vertical rows and columns.

Element

Each entry in a matrix.