1. The problem asks to find the missing side length $x$ using proportions or a table. 2. Given the pairs: $\frac{17.5}{4}$, $\frac{12}{25}$, $\frac{7}{30}$, and $\frac{10}{x}$, we assume these ratios are equal since they represent corresponding sides of similar figures. 3. To find $x$, set up the proportion using the last pair and one known pair, for example, $\frac{10}{x} = \frac{7}{30}$. 4. Cross-multiply: $10 \times 30 = 7 \times x$ which gives $300 = 7x$. 5. Solve for $x$: $x = \frac{300}{7} \approx 42.86$. 6. The scale factor can be found by comparing corresponding sides, for example, $\text{Scale Factor} = \frac{7}{30} \approx 0.233$ or $\frac{10}{42.86} \approx 0.233$. Final answers: Scale Factor = $\frac{7}{30}$ or approximately 0.233 $x = \frac{300}{7} \approx 42.86$