100000×(1+3.85%)^5=120790.42,按照实际利率本利合计120790.42元,120790.42-19517=101273.42,按照基准利率本利合计101273.42元,(101273.42÷100000)^(1/5)-100%=1.0025-100%=100.25%-100%=0.25%,基准利率0.25%