When trying to solve a problem that is totally intimidating, I try breaking it down into smaller parts. This has the benefits of A) making the problems smaller (yay!), and B) increasing the likelihood that I can solve one of the problems. Try it!
(One of the small problems in your request for help is 'how do I compute an average?' Can you manage that one at least? What are the other problems?)
Once you've solved one or several small problems, you A) gain confidence that helps fuel further progress, and B) end up with a better intuitive sense of the shape and size of problems you haven't yet solved, and C) you've given your brain time to mull over some of the other parts, something that often comes in quite handy.
"divide and conquer!"