Question 1117506
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.