债券成本=10%*（1-33%）/（1-2%）=6.84%优先股成本=7%*/（1-2%）=7.14%普通股成本=10%/(1-1%)+4%=15.11%加权平均资金成本=1000/2500*6.84%+500/2500*7.14%+1000/2500*15.11%=10.208%
