Question

The air inside a hot air balloon has an average temperature of 84.3°C. The outside air has a temperature of 15.3°C. What is the ratio of the density of air in the balloon to the density of air in the surrounding atmosphere?
inside / outside = ??

Answer 1

assuming pressure remained constant, if absolute temp doubled, volume would double, and density would be halved, right?

so that sounds like density is in an inverse relation to abs temp.