How do I find out of my OS X 10.9.4 is 32 bit or 64 bit? How do I determine if my OS X 10.9.4 is a 32 bit or 64 bit operating system?
I've looked at "About This Mac" but don't understand what the processor information (i.e. 3.5 GHz Intel Core i7) translates into as refers to "bits.
I do not believe that Mavericks shipped with a 32-bit version. You are probably running 64-bit OS X.

All of the Core i3, i5, and i7 Mac computers have 64-bit processors.

Apple Support document

To determine if you are running a 32-bit or 64-bit version of OS X, open a Terminal and type:

uname -a

On a 64-bit OS, the output will end with RELEASE_X86_64 x86_64. On a 32-bit OS, the output will end with RELEASE_I386 i386.

OSXDaily article