expected frequency

Probability can be used to predict how often a result will happen. The name given to this prediction is expected frequency, and here is its formula:

relative frequency = probability × number of trials

This formula can be used to calculate how many sunny days we can expect during a particular month.

For example, the probability of having a sunny day in April is 0.4. Knowing that there are 30 days in this month, 0.4 × 30 = 12. Therefore, we can expect 12 sunny days in the month of April.