Open General preferences again (cmd/ctrl +K) and change the keyboard increment setting to "7.5 in" (no quotes) so the increment is 7.5 inches. Click OK to accept the setting and close the preferences dialog.
Select the circle with the Selection tool (V) and hold the alt key to duplicate and press the right arrow key to place the duplicate 7.5" away on the right edge of the right ellipse as shown. Open General preferences again (cmd/ctrl +K) and change the keyboard increment setting back to 1 pt. Click OK to accept the setting and close the preferences dialog. This will set them back to default so you don't get a surprise when you use the arrow keys to position an object in another project.