正确。如果将4.9%/12化为49/12000再求解则更好。如下：原式=(1+49/12000)x12x30=12049/12000x12x30=12049x3/100=361.47
原式=（1×12×30）+（4.9%/12×12×30）=360+（4.9%×30）=360+1.47=361.47
