I
looks like a PDF file and I don't think it's encrypted, since I could see raw text, just not the markup. The reason for me to think it looks like a PDF file, is because of this (21st line):
Binomial Dist%PDF-1.4%ÀÈÌÒ
I tried opening it in Acrobat Reader 6.0, but it gave an error.
While typing this, I did a further search in the file itself, and the way is was 'coded', I am certain it is a damaged PDF file, or written in an older format, a format AR 6.0 can't handle. In my search I have found
this PDF file, which explains how to pack a file (usually images) within a PDF file, and the code they describe is exactly like the one I found in the file.
Conclusion: I think this file is either damaged, or written in a format that does not follow the rules that Adobe stated for the PDF-format.
As I said, the raw text is readable, I recommend opening the file in Wordpad instead of Notepad, since there are a type of line-breaks used in the file that Notepad can't handle. When opened the file, just scroll down to view the text.