(1) Frequency: refers to the number of repetitions of a single data in a group of data or the number of data in a group of data within a certain range.

(2) Frequency: it is the ratio of frequency to the number of data contained in the data set.

(3) Frequency and frequency connection: frequency specifically reflects the distribution of data, and frequency reflects the proportion of different data or data in different ranges in the whole data set. They all reflect the distribution of a set of data.

(4) the relationship between frequency and frequency:

(1) The sum of the frequencies of each test result is equal to the total number of tests.

② The sum of the frequencies of the test results is equal to 1.

③ Frequency/total frequency = frequency

2 The meaning of frequency

To some extent, frequency reflects the possibility of an event. The greater the frequency, the greater the possibility of occurrence; On the contrary, the frequency is small and the possibility of occurrence is small.

3. The relationship between frequency and weight:

When calculating the average with weighted average, frequency is the weight.