Can you explain how that calculation works?
Considering the number of significant digits, that's also room temperature.
Sure! Firstly, I considered some semi-random, stereotypically American variables and started trying to mush them together.
I tried going for Calorie conversions compared to football fields of solar irradiance but ended up just calculating how long it would take for the light of the sun to heat up ~1 imperial ton of water from 0 Kelvin to 38 Celsius (assuming 100% efficiency and using the average solar energy per square meter for a whole American football field). It's almost certain that there's a fair bit of error, especially since I said "approximately 2" in my comment rather than the actual value I calculated (which I unfortunately lost, but was somewhere in the ballpark of 2 minutes, 16 seconds), which itself is definitely a fair bit off.
As for the sun temperature percentage being approximately room temp: while that's correct for the number of digits I showed, it's also
slightly more precise than you might think, using an absolute scale. I used Kelvin for both and got 38 C as ~311.15K, and took Wikipedia's value for the surface temperature of the sun as ~5772K. When I divided 311 by 5772 I got 0.0539... which is admittedly about 5.4% rather than the simple 5% (room temperature is about 0.0536, or 5.36%).
All of this was for the purpose of the typical "American units dumb" joke (myself being an American) anyway, so it was never intended to be too exact or well thought out in the first place.
Apologies for making such a long blob of a response. I hope that perhaps it was a enjoyable, or at least tolerable, read.