Given data:
The amount Rosa earned per hour is 12.25$.
The expression for the given statement is,
[tex]1\text{ hour = \$12.25}[/tex]Multiply the above expression by 19 1/2 on both sides.
[tex]\begin{gathered} 19\frac{1}{2}(1\text{ hour)=19}\frac{1}{2}(12.25) \\ 19\frac{1}{2}\text{ hours =19.5(12.25)} \\ =238.875 \\ =238.87 \end{gathered}[/tex]Thus, the amount earned by Rosa in 19 1/2 hours is $238.87.