To determine if the given ratios form a proportion, we need to check if the cross-products of the fractions are equal.
The set of ratios can be written as follows:
- \( \frac{2.25}{10} = \frac{9}{40} \)
- \( \frac{2.25}{12} = \frac{90}{40} \)
- \( \frac{2.5}{10} = \frac{90}{40} \)
We will check each one:
For the first ratio:
- \( \frac{2.25}{10} = \frac{9}{40} \)
Cross-multiplying:
\( 2.25 \times 40 = 90 \)
\( 10 \times 9 = 90 \)
Since \( 90 = 90 \), the first set of ratios is a proportion.
For the second ratio:
- \( \frac{2.25}{12} = \frac{90}{40} \)
Cross-multiplying:
\( 2.25 \times 40 = 90 \)
\( 12 \times 90 = 1080 \)
Since \( 90 \neq 1080 \), the second set of ratios is not a proportion.
For the third ratio:
- \( \frac{2.5}{10} = \frac{90}{40} \)
Cross-multiplying:
\( 2.5 \times 40 = 100 \)
\( 10 \times 90 = 900 \)
Since \( 100 \neq 900 \), the third set of ratios is not a proportion.
Conclusion
Only the first set of ratios is a proportion: \( \frac{2.25}{10} = \frac{9}{40} \).