`sum x=99, n=9, sum (x-10)^(2)=79`, then find, `(i) sum x^(2) (ii) sum (x- overline(x))^(2)`

Find the sum sum_(j=1)^(10)sum_(i=1)^(10)ixx2^(j)

Let r be the range and S^(2)=(1)/(n-1) sum_(i=1)^(n) (x_(i)-overline(x))^(2) be the SD of a set of observations x_(1),x_(2),.., x_(n) , then

If n=5, overline(x)=6, sum x^(2)=765 , then calculate the coefficient of variation.

If x = sum_(n = 0)^(infty) cos ^(2n) theta, " "y = sum_(n = 0)^(infty) sin^(2n) theta and z = sum_(n = 0)^(infty) cos^(2n) theta sin^(2n)theta, 0 lt theta lt (pi)/(2) , then show that xyz = x + y + z [ Hint : use the formula 1 + x + x^(2) + x^(3) +... =(1)/(1 - x) , where |x| lt 1 ]

The sum and sum of squares corresponding to length x (in cm) and weight y (in gm) of 50 plant products are given below: sum_(i=1)^(50)x_(i)=212, sum_(i=1)^(50)x_(i)^(2)=902.8, sum_(i=1)^(50)y_(i)=261, sum_(i=1)^(50)y_(i)^(2)=1457.6 Which is more varying, the length or weight?

If 1+x^(2)=sqrt(3)x , then sum_(n=1)^(24)(x^(n)-(1)/(x^n))^(2) is equal to

If the sum of the series sum_(n=0)^oor^n ,|r|<1 is s , then find the sum of the series sum_(n=0)^oor^(2n) .

The sum of 5x^(2) ,7x^(2) ,8x^(2) ,11x^(2) and 9x^(2) is …………..

The sum of the polynomials p(x) = x^(3) - x^(2) - 2, q(x) = x^(2) - 3x + 1

If for distribution sum(x-7)=3 , sum(x-7)^(2)=57 and total number of item is 20 . Find the mean and standard deviation.