Q2B. - Algebra 1

Question

Use cross products to determine whether each pair of ratios forms a proportion.

$\frac{15}{36},\frac{35}{42}$

Step-by-Step Solution

Answer

No, the pair of ratios $\frac{15}{36},\frac{35}{42}$ do not form the proportion.

Step-1. Define proportion.

If $\frac{a}{b}=\frac{c}{d}$, where a and d are extremes and b and c are the means, then in a proportion the product of the extremes is equal to the product of the means that is., $ad=bc,b,d\ne 0$.

Step-2. Determine the cross products.

Use cross products to determine whether two ratios form a proportion.

$\begin{array}{c}\frac{15}{36}\stackrel{?}{=}\frac{35}{42}\\ 15\times 42\stackrel{?}{=}35\times 36\\ \text{ 630}\ne 1260\end{array}$

Step-3. State the conclusion.

Since, the cross products are not equal, that is., $\text{630}\ne 1260$, therefore the ratios do not form the proportion.