We use fractions, percentages, and decimal numbers to represent the probability of an event. Writing a probability as a fraction, decimal, or a percentage doesn't change it. So 20% chance of rain is the same as . You could use a decimal too, and say there is a 0.2 chance of rain.

Here are some conversions between fractions, percentages, and decimals.

Example 1:
Of 500 professional basketball games, the home team won 275. Thus, the probability that the home team will win a particular game is
275/500 or 0.55 or 55%

IMPORTANT

Creative representation is an indispensable part of solving problems of using different formats to represent probabilistic information. For example, changing risk representations from probabilities to natural frequencies can be enormously useful. Probabilities, especially conditional probabilities, tend to impede human inference, whereas natural frequencies demand less computation, are far more similar to the ways in which we experience numerical information, and appear to help both experts and laypeople.
The representation does part of the reasoning, taking care of the multiplication the mind would have to perform if provided only with probabilities.

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