Comme <math>\(\ln 2 < 1\)</math>(*), <math>\(\frac{\ln 7} {\ln 2 } > \ln 7 > \ln 5\)</math>.

(*) car <math>\(e > 2\)</math>, car <math>\(e=1+1+\frac{1}{2!}+\frac{1}{3!}+\dots\)</math>.