Diagram that summarizes the sample we analyze in this paper. The hatched areas indicate the fraction of spectroscopic binaries among a given population. They represent about 85% of the nonoscillating active RGs, 15% of the active RGs with partially suppressed oscillations, and 2% of the inactive RGs according to our spectroscopic sample. We note that the percentages in the active sample slightly differ from those reported in Table A.1 because they refer to the 370 active stars (with and without detected oscillations) in the present diagram, whereas they refer to the 340 RGs with oscillations in Table A.1.