For the set of 50 observations, the sum of their squares is 3050 , their arithmetic mean is 6. Hence the standard deviation of these observations is

The arithmetic mean of marks in Mathematics for four divisions A, B, C and D were $$80,75,70$$ and 72 respectively. Their standard deviations were $$12,6,8$$ and 10 respectively. Then, division ______ has more uniformity.

If the standard deviation of data is 12 and mean is 72, then coefficient of variation is

140. Given that total of 16 values is 528 and sum of the squares of deviation from 33 is 9158. The variance is