The sum of 12 observations is 600 , then their mean is `"_______"`.

If the sum of 10 observations is 95, then their mean is ______.

The sum of 20 observation is 500, then the mean is ______.

If the sum of 15 observations is 420 then their mean = ..........

The variance of 10 observations is 16 and their mean is 12. If each observation is multiplied by 4, what is the new mean-

The AM of n observations is M. If the sum of n-4 observations is a, then the mean of remaining 4 observations is

The A.M. of n observations is M. If the sum of n - 4 observations is a, then the mean of remaining 4 observations is :