Last updated on April 28, 2016
I also spent a good twenty minutes looking for the Excel 2008 Toolpak addon which Microsoft advertises in their knowledge base, unfortunately this link is broken and there is no place to download and install said addon.
Do not despair! The functionality you seek is actually included in Excel, you just need to go looking for it. If you check your formula bar/builder, you will find that the statistical tools you crave(like the nice correlation tool) are right there.