Q: Could you recommend some books on statistics that would allow me to be more efficient at Business Analytics?
A: Below are some sites that you may find useful.
1) The online copy of StatSoft, the Statistica textbook, a good resource, and it’s organized as a book.
http://www.statsoft.com/textbook/
2) UCLA has an online probability and statistics book, although it may be too elementary for you.
http://wiki.stat.ucla.edu/socr/index.php/Probability_and_statistics_EBook
3) Planet Math has a lot of very useful links. If you scroll down the page for the URL below, you’ll see a link labeled 62-XX, Statistics. (There are plenty of other valuable links too.)
http://planetmath.org/msc_browser/
4) The Kahn has some excellent short videos on specific topics in statistics. More generally, the entire site is very well regarded.
http://www.khanacademy.org/#statistics
It you share the name(s) of the (text)book(s) that you’ve read I can identify which resources may be of the most use to you. As I’m sure you’ve discovered, statistics fractures into a myriad of sub topics just like mathematics. So narrowing this down will let me help you better.