Years ago for a masters project my friend took a bunch of data from an excel sheet and used them in a powerpoint graph. He told me he made the graph in excel then copied it into powerpoint. Now, when I hover over the graph I see the points associated to where my mouse hovers. My friend lost the original excel sheet and is asking me to help pull the data from the powerpoint graph and put it in an excel sheet. 
How would I go about doing this? If theres away to get the points into a json file I can do the rest. I just know nothing about powerpoint graphs.
Right click the chart, choose Edit Data.
If it's an embedded chart, the chart and its workbook will open in Excel.
From there you can File | Save As and save your new Excel file.
Take data points from my power point graph and put them into an excel sheet