It's just a website commonly used for screenshots. It's safe, don't worry. Anyway, I'm afraid I'm not very good at these types of problems, so I can't help you.
Sorry! Someone like CPhill or someone who is much better than I am will come along and help.
I like this site http://davidmlane.com/hyperstat/z_table.html
I got the address for this site from the Stick Topic labeled " Reference Material "