Descriptive Sta...

Let $$\sigma^{2}$$ is variance of following frequency distribution 

The mean and variance of a random variable having a binomial distribution are $$4$$ and $$2$$ respectively , then $$P(X=1)$$ is 

Let $$x_i$$ represents the outcome on a fair die and $$f_i$$ be the corresponding frequency. The variance for random variable $$x_i$$ with following frequency distribution, is

The mean and the standard devition (s.d) of five observations are $$9$$ and $$0$$, respecively. If one of the observations is changed such that the mean of the new set of five obervatons becomes $$10$$, then their s. d. is:

Let $$x_{1},\ x_{2},...x_{100}$$ are $$100$$ above observation such that $$\displaystyle \sum { { x }_{ 1 }=0 } ,\ \displaystyle \sum _{ 1\le i<j\le 100 }^{  }{ \left| { x }_{ i }{ x }_{ j } \right| =80000 } $$ & mean deviation from their mean is $$5$$, then their standard deviation, 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 

Two distributions each of $$5$$ observations having veriance $$4$$ and $$5$$. If their arithmetic mean are $$2$$ and $$4$$ respectively., Find the variance of combined distribution 

If the sum and sum of squares of $$10$$ observations are $$12$$ and $$18$$ resp., then, The $$S.D$$ of observations is :-

The variance of the elements of the row which contains  $$2019$$  is  $$K$$  then the value of  $$3 K$$  is

The variance of first $$30$$ natural numbers, is