Question

in a scale drawing of an airplane, 1 inch represents 5 feet. scale 1 in : 5 ft answer the following. (a) the wingspan of the real airplane is 45 feet. what is the wingspan of the airplane in the scale drawing? inches (b) in the scale drawing, the length of the airplane is 6 inches. what is the length of the real airplane? feet

Explanation:

Step1: Set up proportion for part (a)

Let $x$ be the wing - span in the scale drawing. The scale is $1$ inch : $5$ feet. So we have the proportion $\frac{1\text{ in}}{5\text{ ft}}=\frac{x\text{ in}}{45\text{ ft}}$.

Step2: Solve proportion for part (a)

Cross - multiply: $5x = 45\times1$. Then $x=\frac{45}{5}=9$ inches.

Step3: Set up proportion for part (b)

Let $y$ be the length of the real airplane. The proportion is $\frac{1\text{ in}}{5\text{ ft}}=\frac{6\text{ in}}{y\text{ ft}}$.

Step4: Solve proportion for part (b)

Cross - multiply: $1\times y=6\times5$. So $y = 30$ feet.

Answer:

(a) 9 inches
(b) 30 feet