A cylindrical specimen of some alloy 8 mm (0.31 in.) in diameter is stressed elastically in tension. A force of 15,700 N (3530 lb_f) produces a reduction in specimen diameter of 5 × 10^-3 mm (2 × 10^-4 in.). Compute Poisson's ratio for this material if its modulus of elasticity is 140GPa (20.3 × 10⁶ psi).