How do you work out the probability of an event occuring?

Probability of an event occurring is

the number of wanted outcomes divided by the total number of outcomes.

Probabilities are expressed as decimals or fractions between 0 and 1

You will form a fraction. The top or numerator of the fraction will be the number of ways that the specified event can happen. The bottom or denominator of the fraction will be the number of all the possible events in the situation.

You can work out the probability of an event by creating a fraction e.g. 1/4 means there is a 1 in 4 chance that a specific event will occur out of all possible events. This can also be expressed as a decimal e.g. 0.25 or a percentage e.g. 25%.

The probability of an event occurring can be calculated using different methods depending on the information available. If all outcomes in a sample space are equally likely, you can use the formula:Probability of an Event = Number of Favorable Outcomes / Total Number of Possible Outcomes or Relative Frequency: If you have data on past occurrences of an event, you can estimate its probability by:Probability of an Event ≈ (Number of Times Event Occurred) / (Total Number of Observations)