How to delete other data off my iPhone?

I have an iPhone 4s and currently my iPhone has 3GB of storage taken up by "other" data. I've tried everything. I checked my usage and I delete my e-mails as well as my texts so why do I have so much of this other data? I don't have any apps except for Facebook right now because I don't have enough storage for anything else. I checked the Apple website and nothing on there helps because I've done it already. I've cleared my e-mails, I only have one app so it's not that and there's nothing else on my phone that could take up 3GB of "other" storage… I really don't want to restore my phone but if I have to then I will. Any suggestions would be helpful please?

Is it Jailbroken?