Let `x_(1),x_(2),...,x,` are `n` observations such that `sum_(i=1)^(t)x_(1)=10` and `sum_(i=1)^(n)x_(i)^(2)=260` and standard deviation is `5` then n is equal to

If sum_(i=1)^(n)sin x_(i)=n then sum_(i=1)^(n)cot x_(i)=

If sum_(i=1)^(n)sin x_(i)=n then sum_(i=1)^(n)cot x_(i)=

If x_(1), x_(2), "…......." x_(18) are observation such that sum_(j=1)^(18)(x_(j) -8) = 9 and sum_(j=1)^(18)(x_(j) -8)^(2) = 45 , then the standard deviation of these observations is

Ifx_(1),x_(2),....x_(n) are n observations such that sum_(i=1)^(n)(x_(i))^(2)=400 and sum_(i=1)^(n)x_(i)=100 then possible values of n among the following is (1)18(2)20(3)24(4)27

If sum_(i=1)^(5) (x_(i) - 6) = 5 and sum_(i=1)^(5)(x_(i)-6)^(2) = 25 , then the standard deviation of observations

If sum_(i=1)^n (x_i -a) =n and sum_(i=1)^n (x_i - a)^2 =na then the standard deviation of variate x_i

If sum_(i=1)^(n)(x_(i)-2)=110, sum_(i=1)^(n)(x_(i)-5)=20 , then what is the mean?

If sum_(i=1)^(9)(x_(i)-5)=9 and sum_(i=1)^(9)(x_(i)-5)^(2)=45 then the standard deviation of the 9 items x_(1),x_(2),......,x_(9) is