Saving PDF File at Lower Magnification

I have a PDF file that is at 162% when opened.  I reduce that to 100% but can't find a way to save it at that magnification. If I resave it at the lower magnification, it still opens at the higher value.   If I print it to a new PDF file with Print Adobe and then open that file, it still opens at the higher magnification (162%); it's the same as the original.  I've looked but seen to find out how to save the file at the lower magnification.  I'm using Adobe Acrobat X Pro.