12-foot wall measures 2.5 inches on a scale drawing. In the drawing, a second wall is 9 inches long. What is the actual length of the second wall?

43.2 ft

Step-by-step explanation:

Scale problems usually can be solved with proportions.

The wall whose real and scale drawing lengths you know gives you a ratio of real to scale drawing.

The ratio of real size to drawing size is:

12 ft to 2.5 in.

The drawing size of the second wall is 9 in.

We are looking for the real size of the 9-inch wall.

Let the unknown length be x.

For the 9-inch wall, the ratio of real to drawing size is

x to 9 in.

Now we set the two ratios equal. That is called a proportion.

12 ft to 2.5 in. = x to 9 in.

Use fractions for the ratios.

To solve the proportion, we cross multiply.

2.5x = 108

x = 108/2.5 = 43.2

43.2 ft

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step-by-step explanation: ; )