Weight at Sea Level and at 39,000 feet

What is the difference in weight at sea level and 39,000 feet?

It would cause a weight reduction of .37%

In other words, and object that weights 100 lbs at sea level will weight 99.63 lbs at 39,000 feet above sea level.

“will weight” = “will weigh”

(The mass, of course, will be unchanged)