Given temperature and specific volume data for steam at 40 psia [Ref. 13]: T, F: 400 500

Question:

Given temperature and specific volume data for steam at 40 psia [Ref. 13]: T, °F: 400 500 600 700 800
V, ft3/lbm: 12.624 14.165 15.685 17.195 18.699
Is the ideal gas law reasonable for this data? If so, find a least-squares value for the gas constant R in m2/ (s2⋅K) and compare with Table A-4.