x1 is exactly/approximately (1/x2)-th-portion [li] of x3 by standard x4.
Analogous to xadba, but where the fraction is specified. x2 must be positive; use fractions in order to denote (n/m)-ths of something (where x2 = m/n, in such a case). Typically (but not necessarily), x2 will be filled by rational numbers (and, often, these will be integers greater than 1). Examples: "a/one whole" = "xonba be li pa"; "one-third" = "xonba be li ci"; "two-thirds" = "xonba be li ci fi'u re"; "a quarter/one-fourth" = "xonba be li vo", etc. . See also: xadba (= "xonba be li re"), tezda (= "xonba be li te'o" when in the default mode).