A downhold oil tool experiences critical static biaxial stresses of o = 45,000 psi and oz = 25,000 psi. The oil tool is made of normalized 4130 steel that has an ulti- mate tensile strength of 97,000 psi and a yield strength of 63,300 psi. Determine the factor of safety based on predicting failure by the maximum-normal-stress theory. the maximum-shear-stress theory, and the distortion energy theory.