### Teacher Guide to Probability and Statistics

Statistics is a way of making data useful. Without statistics, our observations of the world around us would be anecdotal - meaning "based on personal accounts" - rather than being something on which we could base estimations or predictions.

WHAT IS STATISTICS?

Statistics uses math to make sense of large volumes of data. For instance, statistics can be used to: predict the likelihood of an event based on previous data, determine the how likely one trait will be seen in tandem with another, and/or summarize information so that it is easier to understand.

ARE THERE DIFFERENT TYPES OF STATISTICS?

Statistics typically takes one of two forms - descriptive or inferential. Descriptive statistics describes the data or observations and can be used to determine whether an event in random. This type of statistics is useful in communicating the results of a study or observations of a population, or sample.

Inferential statistics, on the other hand, uses that information to determine whether occurrences are random or significant (meaning likely to occur again under the same circumstances) and, typically, involves a prediction. In inferential statistics, predications and probabilities about a larger population are drawn from a sample - such as polling 100 people selected randomly (a sample) to determine where the entire school (population) would like to go on a field trip.

WHAT ARE SOME OTHER EXAMPLES OF STATISTICS?

Examples of statistics in practice include:

- Over 51 percent of the population is female
. - One in 10 Americans are unemployed.
- There is a 60 percent chance of rain today.
- If you go to college, you will earn 90 percent more over the course of your life than if you had not.
- There is a high correlation of people who smoke with people who get lung cancer.
- Ron sleeps an average of six hours per night

HOW ARE STATISTICS USED?

Statistics are used by a variety of disciplines - medicine, psychology, education, physics, engineering, science, business, marketing, etc. In practice, statistics may be used to: predict the weather, determine the best marketing technique, calculate the likelihood of side effects, life expectancy, etc. Whether you realize it or not, statistics are part of almost every facet of your life. They are used to determine: who receives scholarships, how much you pay for auto or life insurance, what classes you are placed in, whether you get a raise, the number of police that patrol the area you live in, the frequency of buses on a route, the amount of taxes you pay, etc.