Measures of Dis...

Standard deviation of four observations $$-1, 0, 1$$ and k is $$\sqrt{5}$$ then k will be?

The standard deviation of the data $$6,5,9, 13, 12, 8, 10$$ is 

If the mean deviation about the median of the numbers $$a,2a,....,50a$$ is $$50$$, then $$|a|$$ equals:-

Standard deviation of first $$n$$ odd natural numbers is

For the observations $${ x }_{ 1, }{ x }_{ 2 },{ x }_{ 3 },........{ x }_{ 18, }$$ it is given that $$\sum _{i =1 }^{ 18 }{ ({ x }_{ i }-8)=9 } $$ and $$\sum _{  j=1}^{ 18 }{ { ({ x }_{ j}-8) }^{ 2 }=45 } $$ then the standard deviation of these eighteen observations is 

the coefficient of quartile deviation is 

If $$ N = 10 \sum x = 120 $$ and $$ \sigma _{x} = 60 $$ , the variation coefficient is - 

Mean of variable series $$\bar{x} = 773$$ and mean deviation 64.4 , then coefficient of mean deviation is 

Which one of the following is a false description?

Mean and standard deviation of a data are $$48$$ and $$12$$ respectively. The coefficient of variation is.