Original chamber:
Length, L = 12 in.
Base diameter, d = 5.7 in.
The volume is
V = (1/3)*(πd²/4)*L = (1/3)*(π/4)(5.7 in)²*(12 in) = 102.07 in³
Scaled chamber:
Because the scale factor is 1.5, obtain
Length = 1.5*12 = 18 in.
Base diameter = 1.5*5.7 = 8.55 in
The new volume is
V (1/3)*(π/4)*(8.55 in)²*(18 in) = 344.49 in³
Differenc in volumes = 344.49 - 102.07 = 242.42 in³
Answer: 242.4 in³ (nearest tenth)