Fill in the blanks:
If is the mean of n values of x, then is always equal to _______.
If a has any value other than , then is _________ than
Zero, less than: Given x is mean of n values, the sum of all n terms is denoted by
So, the difference between both of these is always equal to zero, i.e.
And square of the above equation is also equal to zero, so
Now if "a" has a value other than x, then