When should you use a line plot?

Answer 1

A line plot is used when you want to show how one quantity changes as another one does, for instance how many marks pupils get in a test compared to how long they spent revising. The most common alternative is a bar chart, which is used when you are counting things.

A rule of thumb which often works is to look at your data. If one set is words and the other is numbers, use a bar chart. If both sets are numbers, use a line graph.