Answer
$${\text{Not enough information}}$$
Work Step by Step
$$\eqalign{
& \int_1^3 {\frac{{f\left( x \right)}}{{g\left( x \right)}}} dx \cr
& {\text{We cannot apply }}\int {\frac{{f\left( x \right)}}{{g\left( x \right)}}dx} = \frac{{\int {f\left( x \right)} dx}}{{\int {g\left( x \right)} dx}},{\text{ this property or rule }} \cr
& {\text{does not exist, at least we need to know the functions }}f\left( x \right){\text{ and}} \cr
& g\left( x \right)\;{\text{to integrate or other information, so it is not possible solve }} \cr
& {\text{with the information provided}}{\text{.}} \cr
& {\text{Not enough information}} \cr} $$
