1. **State the problem:** We want to find the amount Rosa saves out of 100 dollars, given a ratio table of dollars saved to dollars earned. 2. **Given data:** - Dollars Saved (Part): 3, 12 - Dollars Earned (Whole): 20, 80, 100 3. **Understand the ratio:** The ratio of dollars saved to dollars earned should be constant. 4. **Write the ratio:** $$\frac{3}{20} = \frac{12}{80} = \frac{x}{100}$$ where $x$ is the amount saved out of 100 dollars. 5. **Use the ratio to find $x$:** $$\frac{3}{20} = \frac{x}{100}$$ 6. **Cross multiply:** $$3 \times 100 = 20 \times x$$ $$300 = 20x$$ 7. **Divide both sides by 20:** $$x = \frac{300}{20}$$ 8. **Simplify the fraction:** $$x = \frac{\cancel{300}^{15}}{\cancel{20}^{1}} = 15$$ 9. **Answer:** Rosa saves **15 dollars** out of 100.