Well to keep it simple I could just use LineRenderer, it exactly draws a line through the points you give to it, I don't know how the input is going to be but I'm assuming it would be on a txt file or something similar, which usually there are many ways to read, like using TextAsset for example.
Some details that I should ask is if the positions would be screen position or you just want a specific section of the screen where the graph would be drawn, in that case it would be necessary to make some conversions from the line scale to this subscreen scale.
As you said this would be a simple project but I like to work with Unity and I'm curious about your other assignments so just let me know if you are interested in my proffer.