Plastic engineering problem II

Another problem that was on the exam:

A 5inch long plastic bar molded in Hytrel 5526 with a flexural modulus of 30,000psi@RT. The plastic bar has a cross section of 0.5in by 0.125in and is exposed to a 95 lbs tensile load

a) Calculate the tensile stress and elongation of the Hytrel Bar @RT.

b) Compare the calculated elongation with the elongation value reading from the stress strain curve @RT (73 F) . Explain why these two values are different?