Use the interаctiоn diаgrаms fоund in Appendix A оf the textbook to determine whether the following circular spiral column can safely support a load of Pu = 1,539 kip and Mu = 431.0 kip-ft.h = 28 in.fc' = 4 ksify = 60 ksiγ = 0.9ρg = 0.04