According to 2 CFR 180.990, “preponderance of the evidence” means proof by information that, compared with information opposing it, leads to the conclusion that the fact at issue is more probably true than not.
Preponderance of the evidence is "such evidence as, when considered and compared with that opposed to it, has more convincing force and produces in your minds belief that what is sought to be proved is more likely true than not true."[Williams v. Eau Claire Pub. Sch., 397 F.3d 441, 446 (6th Cir. Mich. 2005)]