A thin convex lens made from crown glass $\;\mu = \large\frac{3}{2}\;$ has focal length f .When it is measured in two different liquids having refractive indices $\;\large\frac{4}{3}\;$ and $\;\large\frac{5}{3}\;$ , it has the focal lengths $\;f_{1}\;$ and $\;f_{2}\;$ respectively .The correct relation between the focal length is :