How wide is the binding supposed to be on the quilt?
Those measurements don't seem right to me.
If you fold it in half after you've sewn the strips, you now have a 1 1/4" folded strip.
You can't really put that on, regardless of the desired binding width, and get a decent 2 sided binding as there is only 1/4" showing of the 2nd fabric.
Is the front supposed to be wider than the back binding?