# Video: Finding the Scale of a Model given Its Model Dimensions and Real Dimensions

An apartment’s ceiling is 19 feet high. However, its height on a scale drawing is only 4 inches. Determine the scale of the drawing.

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### Video Transcript

An apartment ceiling is 19 feet high. However, it’s height on a scale drawing is only four inches. Determine the scale of the drawing.

The scale is the ratio of the length on a drawing to its actual length. Distances on a scale drawing are proportional to distances in real life. For our scale, one inch in the drawing will represent a certain amount of feet in real life. So the distance that we know is that four inches in our drawing represented 19 feet in real life. That’s how tall the apartment ceiling was. Just like our scale, the numerator came from our drawing and the denominator was the actual feet in real life. So in order to solve for 𝑥, in order that that way we can complete our drawing, we need to find the cross product.

So 19 times one is equal to four times 𝑥. Now we multiply. 19 times one is 19, and four times 𝑥 is four 𝑥. Now in order to solve for 𝑥, we need to divide both sides by four.

So 𝑥 is equal to 4.75. So to complete our scale, one inch on the drawing will represent 4.75 feet in real life.