Penguin huddling -Heat transfer mechanisms -Radiation problem

[ctpengage]

Homework Statement

To withstand the harsh weather of the Antarctic emperor penguins huddle in groups. Assume that a penguin is a circular cylinder with a top surface area of 0.34m² and a height of 1.1m. If penguins huddled closely to form a huddled culinder with a top surface area of Na and height h by what percentage does huddling reduce the total radiation loss compared to if 1000 separate identical penguins radiated heat alone.

The Attempt at a Solution

I ended up with the solution of 85%. Can anyone verify this? I just want to see if my solution is right. I'm not looking for anyone to post the full solution just verification. Thanks guys

 

[ctpengage]

cmon guys please help