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Basic Probability

The probability of a sample point is a measure of the likelihood that the sample point will occur. Probability of a Sample Point By convention, statisticians have agreed on the following rules. The probability of any sample point can range from 0 to 1. The sum of probabilities of all sample points in a sample space is equal to 1. Example 1 Suppose we conduct a simple statistical experiment. We flip a coin one time. The coin flip can have one of two outcomes - heads or tails. Together, these outcomes represent the sample space of our experiment. Individually, each outcome represents a sample point in the sample space. What is the probability of each sample point? Solution: The sum of probabilities of all the sample points must equal 1. And the probability of getting a head is equal to the probability of getting a tail. Therefore, the probability of each sample point (heads or tails) must be equal to 1/2. Example 2 Let's repeat the experiment