A Macy's Thanksgiving Day Parade quantity?
*paging sciencefags.
Bagster
Aye, correct.
Use the ideal gas equation, it'll save time. Fortunately, Helium is a Noble Gas(*), so it shouldn't be too far off.
(*) as are you, Goodman. ;-P
Might get expensive...
https://cen.acs.org/articles/96/i12/Helium-supplies-tightening-again.html