Step-by-step explanation:
Volume = 4/3 pi r^3 = 215.634 cm^3
mass = volume * density = 18.07 grams
Assuming freshwater at 1 gm / cc
the ball will displace 215.634 cc and experience a net buoyancy force
equivalent to 215.634 gm - 18.07 gm = 197.6 grams
which is in newtons = mg
newtons = .1976 kg * 9.81 m/s^2 = 1.94 N