Statistics Test...

If the coefficient of variation of some observation is 60 and their standard deviation is 20, then their mean is

The coefficients of variation of two series are $$58$$% and $$69$$%. If their standard deviations are $$21.2$$ and $$15.6$$, then their A.M's are 

The Coefficient of Variation is given by:

The variance of the data:

In a final examination in Statistics the mean marks of a group of $$150$$ students were $$78$$ and the S.D was $$8.0$$. In Economics, however, the mean marks were $$73$$ and the S.S was $$7.6$$. The variability in the two subjects respectively is

If mean of a series is 40 and variance 1486, then coefficient of variation is 

The mean of first five prime numbers is

The S.D. of the following frequency distribution is 

The marks of a class test are given below.
$$28, 26, 17, 12, 14, 19, 27, 26, 21, 16, 15$$. Find the median.

What is the mean of first 8 whole numbers?