Marcel used the multiplication table below to determine that 72:24 is equivalent to 6:18.

Question

A multiplication table. In the row labeled 3, the numbers 3, 6, 9, 12, 15, 18, 21, 23, and 27 are highlighted. In the row labeled 9, the numbers 9, 18, 27, 36, 45, 54, 63, 72, and 81 are highlighted.

What was Marcel’s error?
Marcel did not look at the correct rows in highlighted columns.
Marcel did not choose numbers from the highlighted columns.
Marcel did not put the first and second terms in the same order.
Marcel did not use numbers from the same row to create each ratio.

Answer 1

Marcel's error is that Marcel did not use numbers from the same row to create each ratio.

To determine if two ratios are equivalent, the corresponding terms must be derived from the same reference. In this case, 72:24 and 6:18 are not correctly formed ratios from the highlighted numbers in the multiplication table because they come from different rows, which means the relationships they express are incorrect. The first ratio (72:24) uses numbers from a different context than the second ratio (6:18).