Answer:
Carbon dioxide: 0.04%
Oxygen: 28% (It says 21% online but there's no 21% so I'm guessing that it would be 28% because that is the closest number.)
Nitrogen: 71% (It says 78% online but there's no 78% so I'm guessing that it would vbe 71% because that is the closest number.)
Argon: 1% (It says 0.93% online but if you round up 0.93% it would round up to 1%.)