Answer key posted

[bensoltoff]

@css-model/winter19 I added an answer key to the repo for the computation problems. The first part varies so much in responses, there is no specific key for it. Feel free to compare your solutions to the key. Again, you don't have to use the same code and functions (or even R - Python is fine and there were many great submissions using Python), but this is one way to achieve the desired result.