Chapter 11 Graphs and Probability

• Chapter 11

Chapter Objective:

* Displaying data in a graph highlights some features of the data. Probability measures the likelihood of an event occurring.

Vocabulary:

Double bar graph - A bar graph that presents two sets of data for comparison.

Key - The information on a double bar graph or double line graph, that shows what data set each color or line represents.

Coordinate grid - A coordinate grid is used to locate points on a plane. It has a horizontal number line (x-axis) and a vertical number line (y-axis).

x-axis - The horizontal axis (or number line) on a coordinate grid.

y-axis - The vertical axis (or number line) on a coordinate grid.

Coordinate plane - The plane containing the coordinate grid.

Coordinates - An ordered pair of numbers that gives the location of a point in the coordinate grid; two numbers that describe the position of any point on a coordinate plane relative to the two axes.

Ordered pair - A pair of numbers used to name the vertical and horizontal locations on a grid. The first number tells the distance from the vertical axis. The second number tells the distance from the horizontal axis.

x-coordinate - A number on the x-axis that described the distance of a point from the y-axis. In an ordered pair, the x-axis is the number that is written first. Ex: in ( 2 , 3 ) the x-coordinate is the 2.

y-coordinate - A number on the y-axis that describes the distance of a point from the x-axis. In an ordered pair, the y-axis is the number that is written second. Ex: in ( 2 , 3 ) the y-coordinate is the 3.

Origin - The point ( 0 , 0 ) on a coordinate plane. This is also where the x- and the y-axes intersect at right angles in the coordinate plane.

Straight line graph - A graph in which all of the points fall on a straight line.

Equation - A statement that joins two equal expressions by an " = ".

Combination - Different ways of selecting items, where the order is not important.

Organized list - A list that helps you to record combinations in a systematic order.

Tree Diagram - A branched list, or diagram, showing all possible combinations of outcomes for two or more events.

Favorable outcome - A favorable outcome is a desired result of an event.

Theoretical probability - If each outcome is likely, the theoretical probability of an event is when the number of favorable outcomes is divided by the total number of possible outcomes.

Experimental probability - The probability of an event that is based on the actual results of trials. Experimental probability is equaled to the number of favorable outcomes in an actual experiment divided by the total number of trials.