SOLUTION: In the gift shop of the History of Flight museum, Elisa bought a kit to make a model of a jet plane. The actual plane is 21 feet long with a wingspan of 17.5 feet. If the finished

Question 1117506: In the gift shop of the History of Flight museum, Elisa bought a kit to make a model of a jet plane. The actual plane is 21 feet long with a wingspan of 17.5 feet. If the finished model will be 12 inches long, what will the wingspan be?

Found 2 solutions by Theo, greenestamps:
Answer by Theo(13342) (Show Source): You can put this solution on YOUR website!
the actual plane is 21 feet long with a wingspan of 17.5 feet.

the finished model is 12 inches long.

the ratio of the wingspan to the length is 17.5 / 21.

if the finished model is 12 inches long, then the wingspan of the model would need tobe 17.5 / 21 * 12 = 10 inches.

now the ratio is preserved.

17.5 / 21 = 10 / 12.

cross multiply to get 17.5 * 12 = 21 * 10 which results in 210 = 210.

this indicates that the ratios are equivalent to each other.

you can also see that they're equivalent to each other by finding the least common multiple of each fraction.

17.5 / 21 = 10 / 12

multiply numerator and denominator of 10 / 12 by 1.75 / 1.75 and you get:

10 / 12 * 1.75 / 1.75 = 17.5 / 21.

this indicates the ratios of 17.5 / 21 and 10 / 12 are identical.

Answer by greenestamps(13200) (Show Source): You can put this solution on YOUR website!

Set up a proportion between the length and wingspan of the plane and the model:

21 feet/12 inches = 17.5 feet/x inches

As long as the units in the two fractions correspond, we can have mixed units; and they can be ignored in the computation.

The wingspan of the model is 10 inches.
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