1st, I added a shapefile with projected coordinate system SL_grid_99 to Table of contents.

2nd, I added my points (excel file) to the table of contents. I displayed XY data and exported point data as shapefile. This is the coordinate system for the points:
It seems that both, point and polygon, have the same coordinate system. However, they are not lining up. As can be seen in the map, the points are in the lower left-hand corner:

How can I make the points and polygon line-up?
