Let 
be the radius of the sphere and 
be the error in measuring the radius.
Then, according to the question, = 7 m and = 0.02 m
Volume of sphere (V) = 
Approximate error in calculating the volume = Approximate value of 
= 
= 
= 
= 
= 
= 12.32 m3
Therefore, the approximate error in calculating volume is 12.32 m3.