To determine which two ratios form a proportion, we can check if the cross products are equal. A proportion means that the ratio of one pair is equal to the ratio of another pair.
Let's evaluate the pairs:
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20/4 and 1/5
- Cross products: \( 20 \times 5 = 100 \) and \( 4 \times 1 = 4 \) (not equal)
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20/4 and 2/5
- Cross products: \( 20 \times 5 = 100 \) and \( 4 \times 2 = 8 \) (not equal)
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4/20 and 2/5
- Cross products: \( 4 \times 5 = 20 \) and \( 20 \times 2 = 40 \) (not equal)
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4/20 and 1/5
- Cross products: \( 4 \times 5 = 20 \) and \( 20 \times 1 = 20 \) (equal)
Thus, the two ratios that form a proportion are 4/20 and 1/5.