Final answer:
Using the scale of 1 inch to 3 feet, the model of a 15 ft tall rocket would be 5 inches tall, as calculated by setting up a proportion and cross-multiplying.
Step-by-step explanation:
To find out how tall the model of a 15 ft tall rocket is when using a scale of 1 in: 3 ft, you need to set up a proportion that compares the model's scale to the actual size. The scale given is 1 in (model): 3 ft (actual). Since the actual rocket is 15 ft tall, we set up the proportion as follows:
1 in (model) : 3 ft (actual) = x in (model) : 15 ft (actual)
You then cross-multiply and solve for x:
1 in * 15 ft = 3 ft * x in
15 = 3x
x = 15 / 3
x = 5
Therefore, the height of the model rocket is 5 inches, which corresponds with option a).