Final answer:
To find the length of LM, set up a proportion using the given information and solve for x.
Step-by-step explanation:
To find the length of LM, we can set up a proportion using the given information. Let's call the length of LM x. The given scale length is 8 inches, and the actual length is 20 miles.
So we have the proportion: 0.5 inch / 20 miles = 8 inches / x miles.
To solve for x, we can cross multiply and then divide: 0.5 inch * x miles = 20 miles * 8 inches.
This simplifies to x = (20 miles * 8 inches) / (0.5 inch) = 320 miles.