a<-c(0.2273350,-0.4379338,-0.8180081,-0.2510929,-0.3857628)
b<-c(-0.2790204,-0.9034272,-0.9552218,0.6353196,0.6883501)
c<-c(0.2260877,0.2110204,0.2994247,0.6893214,0.9714620)
用lm((a-c)~(b-c))做出来的是
Coefficients:
(Intercept)            y  
    -0.8470      -0.2116  


而用Excel做出来的是

Intercept	-0.84183
X Variable 1	-0.04558

我想知道是为什么，有没有大神能够解答