个别资本成本:债券:8%/(1-2%)*(1-30%)=5.71%优先股:12%/(1-5%)=12.63%普通股:(14%十4%)/(1-7%)=19.35%留存收益:14%十4%=18%综合资本成本=5.71%*500/1000十12.63%*100/1000十19.35%*300/1000十18%*100/1000=11.72%