Given
15 songs for $5; 45 songs for $15
Procedure
Let's calculate the fraction associated with the two ratios given to us.
[tex]\frac{15\text{ songs}}{5\text{ \$}}=3\text{ songs/\$}[/tex][tex]\frac{45\text{ songs}}{15\text{ \$}}=3\text{ songs/\$}[/tex]In this case, we can see that the two fractions have the same ratio, therefore they have the same proportion.