I can't believe that this is what you have assigned 7th graders. These are stupid time wasting assignments. My son's 6th grade teacher has made him do multiple 'graphs' of bugs bunny and elmo. Do you also make your students color them in with crayons?
A much better assignment would have been to provide the points, in some sort of text file, and have the kids figure out how to get Excel to plot the points. Doing it by hand on 100's of points is a waste of time.