Even if the balls were properly inflated at room temp, then later measuered at 35F or so, that would be less than a 1% delta T (you must use absolute temp here). And thus could only explain a 1% under pressure.
The balls were more like 20% light.
Good try though, I thought about the same issue the other day
Register for free to join our community of investors and share your ideas. You will also get access to streaming quotes, interactive charts, trades, portfolio, live options flow and more tools.