How can you verify that two ratios are in proportion?

To verify that two ratios are in proportion, the most reliable method involves cross multiplying the numerators with opposite denominators. When two ratios, such as ( a/b ) and ( c/d ), are in proportion, it means that the relationship between them can be expressed as ( a/b = c/d ). To confirm this, you can perform cross multiplication by taking ( a \times d ) and ( b \times c ). If the two products are equal (i.e., ( a \times d = b \times c )), then the ratios are indeed in proportion.

This method provides a straightforward check for proportional relationships, as it directly compares the products that arise from the two ratios. Understanding this operation is fundamental in various mathematical contexts, particularly in similar triangles, scaling, and unit ratios. Other methods, such as turning ratios into decimals or adding the denominators, do not consistently determine if the two ratios maintain a proportional relationship.