Answer:
ρ = 800 kg/m³
Step-by-step explanation:
Let the volume of the sphere = V
and the density of the sphere = ρ
density of water , ρ_w = 1000 Kg/m^3
tension in the string is one-fourth the weight of the sphere.
Tension in the rope ,

for the sphere to in equilibrium
T + Weight = buoyant force



ρ = 800 kg/m³
density of the sphere is equal to 800 kg/m³