Under the same conditions, n experiments were carried out. In these n experiments, the frequency m of event A is called the frequency of event A. ..

The ratio of the frequency of a population to the sample size is also called the frequency of this population. With frequency (or frequency), we can know the distribution of numbers.

nature

1. When the number of repeated experiments n increases gradually, the frequency fn(A) is stable and gradually stabilizes at a certain constant, which is the probability of event A. This "frequency stability" is also called statistical regularity.

2. Frequency:

(1) Nonnegativity: 0 is less than or equal to fn(A) is less than or equal to 1.

(2) Normality: fn (ω) = 1 (Note: ω stands for sample space).

(3) additivity.

3. Frequency is not equal to probability. According to Bernoulli's law of large numbers, when n tends to infinity, the frequency fn(A) approaches the probability P(A) in a certain sense.