hmm, heres and idea
lets just try it
experiment: get a scale for weight, a cardboard box, and some balloons
cut the cardboard box so it is a rectangular box shape with an open top and an closed bottom
weigh the box
now keeping the box on the scale fill several balloons with air and toss them into the box that is on the scale
take a reading of of the scale, then calculate how much weight your balloons produced
then calculate the projected weight of lets say 10,000 balloons filled with air
research the approximate weight that will crack the ribs of a average man
and check your 10,000 balloons weight value with this value
this ofcourse discludes the effects of squeezing balloons, balloons breaking, air pressure inside the balloons.. and so forth this would be an (ideal) experiment