Question

topic: understanding proportions
progress
question id: 177943
the length of a picture frame whose width is 3 inches and whose proportions are the same as a 9 - inch wide by 12 - inch long picture frame.

Explanation:

Step1: Set up proportion

The original picture has width - to - length ratio of $\frac{9}{12}=\frac{3}{4}$. The new picture has width 3 inches. Let the length be $x$ inches. The proportion is $\frac{3}{x}=\frac{3}{4}$.

Step2: Cross - multiply

Cross - multiplying the proportion $\frac{3}{x}=\frac{3}{4}$ gives $3\times4 = 3x$.

Step3: Solve for $x$

Dividing both sides of the equation $12 = 3x$ by 3, we get $x = 4$.

Answer:

4 inches