Using the same example of browser usage over the years, you can see that bars have just been placed vertically, but it works ...

It is possible to read data and make comparisons using a bar chart. This type of graph, called a dual bar chart, shows the eye colour of year 7 and year 8 students. Image caption, Using the ...

When choosing intervals for the data sets make sure that they do not overlap and that they include all the data. For example, you could use the following intervals to draw a frequency diagram.