The answer is: 
v ≈ 1272.35 in^3
Sorry if this does not help.
        
                    
             
        
        
        
I believe that the answer would be 45
 
        
             
        
        
        
Answer:
To calculate the mean we need x and f both
 
        
             
        
        
        
" 100% " means "the whole thing",
and "is" can be replaced by "is equal to".
You have said "The whole thing of a number is equal to 61."
or
                       "61 is equal to the whole thing of a number."
The only number that 61 can be equal to is 61.