How many nautical miles does 1 inch represent on a sectional chart, given a scale of 1:500,000?

To determine how many nautical miles 1 inch represents on a sectional chart at a scale of 1:500,000, we can begin by understanding what that scale means. A scale of 1:500,000 indicates that 1 inch on the map represents 500,000 inches in the real world.

First, we convert inches to nautical miles. There are 63,360 inches in a mile, and there are 1.15078 statute miles in a nautical mile. Therefore:

1. Convert 500,000 inches to miles:

• 500,000 inches ÷ 63,360 inches/mile = approximately 7.875 miles.

2. Convert statute miles to nautical miles:

• 7.875 miles ÷ 1.15078 miles/nautical mile ≈ 6.84 nautical miles.

Rounding this value gives approximately 7 nautical miles for every inch on the sectional chart. Thus, the correct answer is that 1 inch on a sectional chart with a scale of 1:500,000 represents around 7 nautical miles, making that the most accurate answer choice in this scenario.