Answer:
The new volume is 7,606.96 Liter.
Explanation:
The combined gas equation is,

where,
= initial pressure of gas in the balloon = 0.918 atm
= final pressure of gas in the balloon = 0.0012 atm
= initial volume of gas in the balloon = 
= final volume of gas in the balloon = ?
= initial temperature of gas in the balloon = 
= final temperature of gas in the balloon = 
Now put all the given values in the above equation, we get:



The new volume is 7,606.96 Liter.