If you need to create a Line Chart and Scatter Plot in Excel, read through this article. We have also explained which one is right for you.

Each .csv contains a set of data points (say, from column 4, where rows 4, 5 and 9 are individual subjects of the graph) that I want to plot with the date along the X axis. Basically, what I want ...

You can make an Excel scatter plot assigning one of the variables in each record to the x-coordinate and one to the y-coordinate on a standard graph axis.