There is no such thing as NumericalQ, I think you mean NumberQ or NumericQ?
ClearAll[ReV]
ReV[expr_]:=VectorQ[expr,NumberQ[#]&&(Head[#]===Real||Head[#]===Integer)&]
ReV[{1,2,3}]
ReV[{1.0,2.0,3.0}]
ReV[{1.0,2,3,4.0}]
ReV[{a,1.0,2,3,4.0}]
ReV[{Sqrt[2],1.0,2,3,4.0}]
ReV[{1/3,1.0,2,3,4.0}]