Apparently, (according to outside information, not this poll) 7 is the most oft picked number by humans. It makes one wonder why there are the 7 deadly sins, 7 great/ancient wonders of the world, and so on. Also, 7 x 6 = 42. 76 - 42 = 34. 34 backwards is 43. Also, 4 + 3 = 7. 7 is humanity's favorite number as a whole (not necessarily individually).
I voted for 9.