We all know how difficult it is to identify the sex of these fish, so please post a picture in here and we'll try to help you (or at least give an educated guess!).
Two things here, what size are these fish? It is hard to sex them until they get to about 2.25 to 2.5 inches unless you vent them from underneath (see their sex organs).
More importantly, fish number 2 looks to be a snub-nose and you should return it for another fish or a refund. This is an uncommon deformity which is not genetic, however at the prices charged for zebras you re entitled to receive undeformed fish. In fact, in the group picture it appears as if two fish, the ones on each end, are snubnosed. (Fishes #1 and #2.)
To get more information on snubnosed zebras, do a site search for the term "snub" (w/o the quotes).
What makes the common person uncommon is common sense.