Chapter Outline

Data

This chapter is about ways of organizing data, or numerical information:

• A graph is a diagram that shows relationships among numbers.
• A table is an organized chart or list of numbers.
• Statistics is a name for organizing and interpreting data.
• Probability is a number that expresses the likelihood that a specific event will happen.

Graphs and Tables

• A circle graph represents one whole amount, such as 100%. Each pie-shaped piece of a circle graph represents a part of the whole.
• A bar graph organizes information along a vertical axis that runs up and down one side and a horizontal axis that usually runs along the bottom.
• A line graph, like a bar graph, has information on both a vertical axis and a horizontal axis. The changing data is shown on a continuous line rather than on a set of bars.
• A table is a list of numbers displayed in columns and rows.

Probability

Probability is the chance of something happening:

• The probability of an event is the ratio of the number of favorable outcomes to the total number of possible outcomes.
• Probability can be dependent on an earlier situation.

Statistical Analysis

There are three ways to analyze a set of numbers:

• The mean (or average)—a total divided by the number of items that make up that total.
• The median—the middle value of an odd number of numbers and halfway between the two middle values of an even set of numbers
• The mode—the most frequently occurring number in a set.