1100*(1-5%)=1000*9%*(1-25%)*(P/A,K,5)+1000*(P/F,K,5)
1045=67.5*(P/A,K,5)+1000*(P/F,K,5)
因为本题是溢价发行,所以其票面利率大于其市场利率,
假设K=5%
67.5*4.3295+1000*0.7835=1075.74
假设K=8%
67.5*3.9927+1000*0.6806=950.11
(K-5%)/(8%-5%)=(1045-1075.74)/(950.11-1075.74)
(K-5%)/3%=0.244
(K-5%)=0.0073
K=5.73%