How do i enable 3g on my Motorola Photon 4g?

[AC Question]

I'm not getting any 3g (or now 4g) data. It said 3g was not turned on. I ran the 3G connection test from the Sprintzone app and it sends me to the the Wireless & network settings screen, only there is no 3G enable. How do I turn 3G back on (& how did it get turned off so I don't do it again?)?