Since 4 pounds of flour costs $2.60, we have that:
[tex]\begin{gathered} 4\text{pounds}\to2.60 \\ x\to1 \end{gathered}[/tex]Where x is the amount of flour you get for 1 dollar.
We can rewrite the expression above as follows:
[tex]\begin{gathered} \frac{4\text{pounds}}{2.60}=\frac{x\text{ pounds}}{1} \\ \Rightarrow x\text{ pounds}=\frac{4pounds}{2.6}=1.53846\ldots \\ \Rightarrow x\approx1.54 \end{gathered}[/tex]Then, we get 1.54 pounds of flour per dollar