Answer:
y = 108
Explanation:
given y ∝ x² then the equation relating them is
y = kx² ← k is the constant of proportion
to find k use the condition when x = 4 , y = 48
48 = k × 4² = 16k ( divide both sides by 16 )
3 = k
y = 3x² ← equation of proportion
when x = 6 , then
y = 3 × 6² = 3 × 36 = 108