I am currently trying to figure out how a set of points were plotted without full XY coordinates. I was given Y coordinates, but not X and there are points plotted on a map. I think these points were just placed by drawing points/creating features. Is there any way I can figure out the X coordinates from the Y?
Found out the solution. The shapefile was read only, I couldn't figure out how to edit the attribute table or create new features. In order to remedy this you have to exit ArcMap. Open the file explorer (or ArcCatalog) go to folder containing shapefile > properties > uncheck read only. Once the shapefile was editable a tool called "Add XY coordinates" was used under Data Management > Features > Add XY coodinates. Input desired shapefile and it outputs XY coordinates in the attribute table.