Posted by Emily on Tuesday, January 25, 2011 at 2:23pm.
The ratio between successive terms is
(704/11)^(1/6) = 2 (or -2)
Yes, two answers are possible.
One series would be
11, 22, 44, 88, 176, 352, 704
and the other
11, -22, 44, -88, 176, -352, 704
You do the adding