# Statistical Class

## Statistical Class

Each of the successive intervals in which is divided the total interval of variation of a quantitative statistical variable.

The size of these intervals is called the amplitude of the statistical class.

### Example

 Mass of 190 students at school Mass (in kg) Numbers of students [36, 38) [38, 40) [40, 42) [42, 44) [44, 46) [46, 48) [48, 50) [50, 52) 14 20 25 35 44 32 15 5 Total 190

Based on this table, we grouped the data into 8 classes.

The amplitude or dimension, or range) of each class is 2.

For the class [36, 38), the lower bound is 36 and the upper bound is 38.

The frequency of the class [36, 38) is 14.

The range of the distribution is 23, because: E = 52 − 36 = 23.