Question

A family has annual loan payments equal to 30% of their annual income. During the year, their loan payments total $15,680. What is the family's annual income? (Round your answer to the nearest cent.)

Answer 1

 First, set up a ratio: $\frac{30}{100} = \frac{15,680}{x}$
The first fraction is the percentage (30% and $\frac{30}{100}$ are the same thing) and the second is the loan payment (which is equal to the 30 in the first fraction) over their annual income ($x$).
 First you divide $15,680 by 30, then multiply that quantity by 100. The value calculated then replaces $x$ in your second fraction: $\frac{30}{100} = \frac{15,680}{52,266.67}$