Probability is a mathematical field measuring the likelihood that something will occur. Methods to determine probabilities can used to determine how likely it is to get heads when flipping a coin or to buy the winning ticket in a lottery. Probabilities are also used by meteorologists when they make weather forecasts and by insurance companies when they decide the price of an insurance.
In this chapter, we will first describe the terminology and calculation methods for determining the probability of one event. This terminology includes outcome, desired outcome, sample space, and complement. If will also be described how the probability of the complement relates to the probability of the desired outcome.
After that we will move on to explore methods for deciding the probability of two events occurring. When doing that terms such as independent and dependent events will be introduced together with conditional probability and two-way frequency tables. Some of the methods in this chapter can also be further expanded and can provide a tool for finding the probability of three or more events occurring.
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Subchapters:

• Describing Theoretical Probability
• Finding the Probability of Two Events