I want to be a Data Analyst, but my math is pretty weak. The instructors of a course I'm doing said Algebra would be enough to understand and follow along with a Statistics course (through Excel, so they'll probably teach me to compute the stuff there rather than the internal mechanics), but I want to go through Arithmetic just to make sure the fundamentals are solid enough.

I've heard of Khan Academy, and while it looks good, I was wondering if there's anything you would recommend over it. And yes, I plan to do exercises as I go through different subjects to drill in the knowledge gained (if you have a site in mind for problems to solve, feel free to share it).

EDIT: If possible, I'd also want to learn basic Probability as well.