Chapter 6.3, Problem 8E

To determine

To evaluate: the proportions $\frac{60}{15}=\frac{12}{y}$ by cross products property.

Answer to Problem 8E

The answer of the proportions $\frac{60}{15}=\frac{12}{y}$ is $y=3$ .

Explanation of Solution

Given information: The provided proportions are $\frac{60}{15}=\frac{12}{y}$ .

Calculation :

The product of the numerator of one ratio and of the denominator of the other is known as a cross product. Cross products can be used to determine whether the ratios form a proportion or not. If the cross products are equal, then the ratios form a proportion.

  $\begin{array}{l}\frac{60}{15}=\frac{12}{y}\text{ [Write the proportion}\text{.]}\\ 60\times y=15\times 12\text{}\text{}\text{ [Apply cross products property}\text{.]}\\ 60y=180\text{ [Multiply}\text{.]}\\ \frac{60y}{60}=\frac{180}{60}\text{ [Divide each side by 60 to place the variable on one side of the equation}.]\\ y=3\text{ [Simplify}\text{.]}\end{array}$

Hence, the solution of the proportions $\frac{60}{15}=\frac{12}{y}$ is $y=3$ .