Problems with re-sizing images.

[Blighty]

Try this:

Setup a *new* image as in the image below.

Set the Image Size to 4 x 2 inches
Set resolution to 300 dpi
Gimp will calculate the image size in pixels for you (1200 x 600 pixels)
(Remember Gimp works in pixels)
Call this layer Background.

(You can alter the Image Size in inches and/or the resolution. Gimp will recalculate the size in pixels.)

You will not use this Background layer directly. It is there to give an indication of size for your images.

Now Use (File > Open As Layers) to open one of your images. It will open as a new layer above the Background Layer.

Use the Scale Tool  or  (Layer > Scale Layer) to scale your image to the size of the Background layer.

When complete SAVE as a .xcf file (this preserves the layers) and EXPORT as .png. Use the .png file in Word.