In the context of this exercise, applying stacked bar charts, when do we usually apply them?
In general, stacked bar charts applied when you want to see and compare individual values with each other, as well as see how they count toward an overall total. Usually, stacked bar charts are applied in two common cases, which are given as follows.
One common case is when you want to see how much the individual values count toward a set total, and this is usually referred to as a 100% stacked bar chart. In this exercise, we applied this type of stacked bar chart, where each bar has the same height of 30, for the total number of students, where the individual values were the number of students that got each letter grade.
Another common case for applying stacked bar charts is when you do not apply the 100% stacked bar chart, such that the total values are not set. For example, say you were plotting the amount of time spent on chores per day. Each individual value can be the hours spent on a certain chore, and the total height of each bar can be the total hours spent on chores in a single day. Some days you might spend 5 hours total, while on others less or more, resulting in bars of differing total height.