Question

A model plane is 4 in tall. If it was built with a scale of 4.5 in : 18 ft, then how tall is the real plane?

Answer 1

A model plane is 4 in tall.

It was built with a scale of 4.5 in : 18 ft

`(4.5\: in)/(18\: ft)`

To find how tall is the real plane, we can set up the following proportion

`(4.5\: in)/(18\: ft)=(4\: in)/(x\: ft)`

Where x is the real height of the plane in feet.

`\begin{gathered} (4.5)/(18)=(4)/(x) \\ x\: \cdot(4.5)/(18)=4 \\ x\: =4\cdot(18)/(4.5) \\ x=16 \end{gathered}`

Therefore, the real height of the plane is 16 feet.