I have a set of data and supposed to see if the linear model $$Y=\beta_0 + \beta_1 X_1 + \beta_2X_2 + \varepsilon$$ fits the data (mydata, using R) below is a scatter plot.
> mydata=read.table(....) > pairs(mydata)
I am not very good at interpreting scatter plots(yet). From the output, how can i tell whether the model fits? thanks