I've been using this handy-dandy calculator...it has piece sizes, and calcs for border & backing
vrya.net/quilt/flash/QuiltCalc_Loader.html

10.5 yards is what I came up with and about 1yard for 2 1/2" binding.

yep, I get 10.5 yds, as well....but I'd probably go with 11 yds, especially if it was being done on a Long Arm. they need a bit more to "hook it up", so to speak.

I got 9 yards, 3 x 42 = 126'which is more than enough to cover the 115. 3 x 3 = 9 yards