To determine which two ratios form a proportion, we need to check if the cross-products of the two ratios are equal.
- 420 and 15: The ratio is \( \frac{420}{15} \).
- 4 over 20 and 1 fifth: The ratio is \( \frac{4}{20} \) and \( \frac{1}{5} \). We can simplify \( \frac{4}{20} = \frac{1}{5} \), so they are equal.
So, \( \frac{420}{15} \) does not equal \( \frac{1}{5} \), thus they do not form a proportion.
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204 and 25: The ratio is \( \frac{204}{25} \).
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20 fourths and 2 fifths: The ratio is \( \frac{20}{4} \) and \( \frac{2}{5} \). We can simplify \( \frac{20}{4} = 5 \) and \( 2/5 \) is not equal to \( \frac{5}{1} \), thus they do not form a proportion.
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420 and 25: The ratio is \( \frac{420}{25} \).
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4 over 20 and 2 fifths: \( \frac{4}{20} \) simplifies to \( \frac{1}{5} \). Therefore, this comparison is \( \frac{420}{25} \) and \( \frac{1}{5} \), which definitely does not hold.
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204 and 15: The ratio is \( \frac{204}{15} \).
After checking all options:
None of these pairs of ratios form a proportion that meets the criteria.
If I were to identify another pair, for completeness, it would be best to re-evaluate other options, but out of the options given, none obviously form matching proportions.
If you want correct proportions, please check the ratio notations and clarify if any modifications were incorrect in their simplifications.