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Question
A student said that the ratios `3/4` and `9/16` were proportional. What error did the student make?
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Solution
Two ratios a : b and c : d are said to be proportional
if `a/b = c/d` or ad = bc.
But the given ratios `3/4` and `9/16, 3 × 6 ≠ 4 × 9`
Hence, the ratios are not proportional. To make a ratio proportional to another ratio, we just simply multiply both numerator and denominator by the same number.
Here, the student had multiply numerator by 3 and denominator by 4, which is incorrect.
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