Intensity of radio waves during the war

"The Technological Revolution

The inventory of technological innovation in store during the Great War is huge, diverse, successful, and goes beyond the limits of popular topics. [...] American specialists developed a system of radio telegraphy capable of guiding all air traffic in a 200 km radius - the first control towers. [...]"

Determine the quotient of the intensity of the waves $$\frac{I_{1}}{I_{2}}$$, when at 1 km (position 1) and at 200 km (position 2) from the control tower. Consider that the tower trasmits uniformly to all directions and that there's no energy dissipation.

Details and assumptions

1. Take $$\pi = 3.14$$.
2. This is a discursive problem taken from a brazilian university (UFSC) admission test.

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