dumb GIMP question

[Lynn David Newton]

Any GIMP experts out there? This may seem like a dumb
question, but so help me, I've tried this at least ten
different occasions and I can't figure out how to do
it.

I have a high-resolution JPEG picture: 1600x1200
pixels. All I want to do is reduce it: save it as a
1024x768 or maybe 640x480. I know about Tools ->
Transform Tools -> Crop & Resize. That works great for
cropping, but how do I simply shrink the whole image?

I used to use the shareware program xv for this. You
can select size and say 50% or whatever, and it will
resize the image retaining the aspect ratio.

There's gotta be something simple that I'm missing.

-- 
Lynn David Newton
Phoenix, AZ