Let x be the amount of dollars that 109.13 pesos was worth. Since the ratio of dollars to pesos is 1 to 19.61, then:
[tex]\frac{x\text{ dollars}}{109.13\text{ pesos}}=\frac{1\text{ dollar}}{19.61\text{ pesos}}[/tex]Solve for x:
[tex]\begin{gathered} \Rightarrow x\text{ dollars}=\frac{1\text{ dollar}}{19.61\text{ pesos}}\times109.13\text{ pesos} \\ =\frac{109.13}{19.61}\text{ dollars} \\ =5.565017848...\text{ dollars} \\ \approx5.57\text{ dollars} \end{gathered}[/tex]Therefore, the answer is: 5.57 dollars.
