difference between the fitted values calculated by the fitted.values and the fitted values calculated from the estimated model

[<Jo.Jiao@csiro.au>]

 

Hi, here is a simple question about linear regression. Just say I have fitted a simple regression model: y=b0 + b1*X

The estimates of b0 and b1are bo_hat and b1_hat. I have noted that the fitted values calculated using the function fitted.values are differenct from those calculated

using bo_hat+ b1_hat*X . The difference between the two kinds of fitted values is not big, but I suppose they shall be exactly the same. Can someone give me a clue?

 

Thank you very much for your help.

 

Jo Jiao

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