In mathematics, x̂ often refers to the unit vector in the +X direction. In statistics, it can also represent the predicted value for x, consistent with the hat notation.[3]
^Bergsland, Knut (1994). Aleut Dictionary = Unangam Tunudgusii: an |D with hook and tail|ᶑ lexicon of the Aleutian, Pribilof, and Commander Islands Aleut language. Fairbanks, AK: Alaska Native Language Center, University of Alaska. ISBN978-1-55500-047-9.