Sure, it's possible. I wouldn't count on it (say, buying a dress that's too small with the intent of losing inches to fit in it), because bodies lose differently, depending on where you put on fat last and just body strangeness. But it IS a possibility, if that's where you lose the majority of your weight.

I have only been working out a little over 3 weeks and all my pants are starting to fall off me. I don't think I have lost 4 inches, but it is noticeable ( for me anyway). Even if you don's lose 4 inches, I am sure you can lose enough to tell a difference. Good Luck!

If we count 5cm per hip, I think it can be done!
Lots of exercises and healthier food intake!

I have fairly small hips for my size, and that’s one of the first places I lose weight. Like Jenny, my pants are also falling off of me after three weeks (and I just started exercise yesterday), though I’m not measuring this time. From past experience the most I’ve ever lost in my hips inch wise was 2 ½ (and that was after 20 lbs.). It basically depends on where you gain/lose first. It’s true that I lose there first, but it’s also where I gain last so this may not apply to you at all. If you have more to lose in your hips you may be able to lose more in that amount of time than I did; then again if you have more to lose in that area you may lose inches there more slowly than I did. It really all depends on your body, there’s no way to predict. Wow, that was a lot of rambling; I hope it made a little sense