How do I change images to 1024 x 768 DPI and still keep their proportions accurate? ?

My MFA program application requires me to send 20 still images (of paintings) on CD-Rom format as my portfolio and requires the images be at 1024 x 768 @ 72 DPI. I have Photoshop (CS3) but am not very skilled with it; when i tried to alter the images to these proportions they end up looking skewed. How to I keep their proportions but re-size them to fit the school's requirements?How do I change images to 1024 x 768 DPI and still keep their proportions accurate? ?
1024 x 768 is a 1.33, or 4:3 ratio.



If your current images are not sized at the same ratio (take the current width divided by height to find out), you won't be able to transform them to 4:3 without distorting them.



You could crop them to an appropriate size, or simply re-scan them at the correct resolution. Rescanning is probably the best option for you here.