While you're at it, please shift to metric! Feet for altitude, nautical miles for distance, statute miles for visibility, metres for runway visual range (most often)...
Take a plane that has a glide ratio of 1:10, say. It's 1 km high. How far can it glide? 10 km.
Now it's 3000 ft high. How far can it glide, in nautical miles?
Take a plane that has a glide ratio of 1:10, say. It's 1 km high. How far can it glide? 10 km.
Now it's 3000 ft high. How far can it glide, in nautical miles?