Question

Question 120

What's the Error? A student said that the ratios $\frac{3}{4}and\frac{9}{16}$ were Proportional. What error did the student make?

Answer 1

Two ratios a : b and c : d are said to be proportional, if $\frac{a}{b}=\frac{c}{d}$ or ad = bc.
But in the given ratios $\frac{3}{4}and\frac{9}{16},3\times 16\ne 4\times 9$.
Hence, the ratios are not proportional. To make a ratio proportional to another ratio, we just simply multiply both numerator and denominator by same number. In our given case, student had multiply numerator by 3 and denominator by 4, which is incorrect.