if it were me, I would soak this in hot water and then wash it to shrink the piece.
I would allow two inches per yard for shrinkage in each direction. In my experience, fabrics usually only shrink in one direction, but I don't know whether it will be lengthwise or crosswise ahead of time.
You will also need to allow extra around the edges - how are you planning to have this quilted? Many long-armers want so much extra around each side. If that is what you are planning to do, contact the person to see what he/she prefers.
So - let's assume that you are going to send this to a long armer that wants 8 inches all the way around to be able to fasten it to the frame.
8 inches on all sides may be "a lot" for attaching to a frame -
96 + (2.67 yards x 2 inches for shrinkage) + (2 x 8 inches for attaching to frame)
96 + 6 + 16 = 118 inches
84 + (2.33 yards x 2 inches for shrinkage) + (2 x 8 inches for attaching to frame)
84 + 5 + 16 = 105
so - now I would divide 118 by 36 = 3.28 yards
I would buy at least 3-1/3 yards of 108 inch fabrics in case the ends are cut crooked or are off-grain.
But - I tend to buy "generously" rather than "skimpily"