What Is Probability? How Is Probability Used to Determine Statistical Significance?

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WHAT IS PROBABILITY? HOW IS PROBABILITY USED TO DETERMINE STATISTICAL SIGNIFICANCE? The concept of probability can be viewed in many ways. There is not even a general agreement as to what is meant by Probability. Probability is a measure of how likely it is that a given event or behavior will happen. Probability is conventionally expressed on a scale from 0 to 1, a rare event has a probability close to 0, and a common event has a probability close to 1. The probability of an event is often defined as a number between one and zero. In reality however there is virtually, nothing that has a probability of 1 or 0. Could you say that the sun will certainly rise in the morning? Your answer may be “Yes”. But what if an extremely unlikely event destroys the sun? What if there is a nuclear war and the sky is covered in ash and smoke? We often round the probability of such things up or down because they are so likely or unlikely to occur, that it's easier to recognize them as a probability of one or zero. When a coin is tossed, there are two possible outcomes: heads (H) or tails (T) we say that the probability of the coin landing H is 1/2. And the probability of the coin landing T is 1/2. The formula for probability of an event happening = number of ways it can happen divided by total number of outcomes. Probability is one of the two approaches to conducting significance tests. By using probability theory we can estimate the probability of being wrong, if we assume that our finding a relationship is true. If the relationship is being small, then we say that our observation of the relationship is a statistically significant finding. Statistical significance is determined by calculating the probability of error (p value) by the (t ratio). Statistical significance is the number, called a p- value that tells you the probability of your result being observed,

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