# Histogram

## Histogram

Diagram that uses juxtaposed bars to represent the distribution of a continuous quantitative statistical attribute on a given sample.

For each class, we draw a rectangle for which the side along the x-axis has a width that is the amplitude of the statistical class and for which the area is proportional to the frequency of each class.

### Example

EXAMPLE
Consider a distribution of some students’ grades on a math test in which the results obtained by the students were grouped by classes of 10 percentage points.

Table

 Classe Effectif [10, 20) 5 [20, 30) 12 [30, 40) 22 [40, 50) 45 [50, 60) 51 [60, 70) 25 [70, 80) 15 Total 186

Histogram
In this example, we can see that each bar is the same width and that its length (or height, if the bars are vertical) corresponds to its frequency. The classes are only represented by their limits here.

These classes are: [10, 20), [20, 30), [30, 40), [40, 50), etc.