I'd say ... male. It's easier to tell if you have several chicks from the same batch to compare, but let's go with "male."
With newly hatched Barred Rocks, there are two tried-and-true sex-linked indicators:
1. Males have a large, splotchy white spot on the top of the head. Females have a smaller spot.
2. Males have lighter legs, while females have darker legs, with with a sharp transition from blackish to yellow at the toes.
In the feed store, it's best to pick out the most obvious pullets or cockerels, and not take a chance on the in-betweeners.