Comments on Modules 3-4 - Clint Olson

[laderast]

-- Typographical errors --
module3-line7: "Module3.RData" should be "module3.RData"

-- code errors --
module4-line143-145: all references to "x" should be "vec"..or the function parameter "vec" should be
changed to "x"

-- comments --
Module 3:
- For those of us who are new to R, it might be nice to have the answers to the comment questions
placed in a separate file for reference.

- For modules 1 and 2, the final problem file was empty except for the problem instructions.  I was a
  little surprised to find that the solution to the module 3 final problem was already in the file.  
  Perhaps having two files, one for the student to fill in for them selves and another containing the
  solution for reference would be useful.