Relative frequency - GCSE Maths Definition

In GCSE Mathematics, relative frequency refers to a probability that is found using the observed results of a (repeated) experiment.

To find the relative frequency of an event, we would use the number of times that event occurred, and write it as (the numerator of) a fraction with its denominator being the total number of observed results (trials).

For example, if we did not know the numbers, nor colours, of counters in a bag, we could repeat the experiment of drawing a counter randomly from the bag 100 times (one counter at a time, which is then replaced in the bag) and record the colours seen; if we observe 65 red counters, we would say the relative frequency of drawing a red counter is .

Relative frequency is predominantly used when theoretical probabilities cannot be applied - for example, finding the probabilities of each outcome on a biased dice. The probabilities of different weather events are based on prior experiences/recordings.

The higher the number of times the experiment is repeated (trials), the more realistic the relative frequency should be to the actual probability.