What does the term 'relative frequency' refer to in statistics?

Relative frequency in statistics is a way to express how often a specific event occurs compared to the total number of trials or observations. It is calculated as the number of times the event occurs divided by the total number of observations, resulting in a fraction or percentage. This metric allows researchers to understand the likelihood of an event relative to all possible outcomes, providing valuable insight into the data collected during an experiment.

The other choices present different concepts that do not accurately define relative frequency. The first option pertains solely to the count of occurrences without considering the total number of observations, which is key to understanding relative frequency. The third choice refers to the concept of residuals, which involves comparing observed and expected frequencies in statistical tests, rather than how often an event occurs. Lastly, the fourth option discusses rare events in large datasets, which is a different area of focus and not specifically related to calculating relative frequency.