Final answer:
To find the length of the actual plane, use the scale ratio of the model plane and set up a proportion. The length of the actual plane is 160 feet.
Step-by-step explanation:
To find the length of the actual plane, we can use the scale ratio of the model plane. The scale ratio is given as 1.5 in to 20 ft. This means that for every 1.5 inches on the model plane, the actual plane is 20 feet long.
If the model plane is 12 inches long, we can set up a proportion to find the length of the actual plane:
1.5 in / 20 ft = 12 in / x ft
Cross-multiplying and solving for x, we get:
x = (12 in * 20 ft) / 1.5 in = 160 ft
The length of the actual plane is 160 feet.