Statistics Test...

Standard deviation of $$3, 5, 7, 9, 11, 13$$ is?

The variance of first $$20$$- natural numbers is?

In an experiment with $$10$$ observations on $$x,\displaystyle \sum { x=60, } \displaystyle \sum { { x }^{ 2 } } =1000$$ one observation that was $$20$$ was found to be wrong and was replaced by the correct value $$30$$ then the correct variance is 

Variance of the data given below

For a series the information available is $$n=10$$, $$\displaystyle\sum x=60, \displaystyle\sum x^2=1000$$. The standard deviation is?

The standard deviation of $$15$$ terms is $$6$$ and each item is decreased by $$1$$. Then the standard deviation of new data is?

For r.v. X whose p.m.f. is

The standard deviation of $$1, 2, 3, 4, 5, 6, 7$$ is?

If the variance of the data 2,4,5,6,8,17 is 23,33, then variance of 5,11,14,17,23,50 is ________________.

In a series of $$100$$ observations, half of them is equal to $$p$$ and remaining half equal to $$-p$$ if the standard deviation of these observations is $$10$$ then $$|p|=$$__