Look at the source code for the R function lm. (Hint: you can see a function’s source code by printing the function name without any parentheses or arguments.) The model fitting routine is done in...

Look at the source code for the R function lm. (Hint: you can see a function’s source code by printing the function name without any parentheses or arguments.) The model fitting routine is done in just one function call; the rest of the function is used to pre- and post-process the results. Identify the model fitting line. What function is being called?