4/3 as a fraction is 1 1/3. The volume of a circle is not a thing, so I am going to assume your asking volume of the balloon.
9 = radius
The volume is of the balloon is 4/3 x 9 x 9 x 9 x 3.14 (pi)
Volume = 3052.08 cubic inches
If you are asking for area of circle
Area of Circle = 9 x 9 x 3.14
Area = 254.34 sq. inches