Find the cov (X, Y) between X and Y, if `sum u_(1)v_(1) = 55 and n = 11`, where `u_(1) and v_(1)` are deviation of X and Y series from their respective means.

If n= 12 and sumu_(i)v_(i)= 60 , where u_(i)" and "v_(i) are deviations of X and Y series from their respective means, then cov(X, Y) is

Given r = 0.8, sum xy = 60 , sigma_(y) = 2.5 and sum x^(2) = 90 , find the number of items, where x and y are deviation from their respective means.

Sum of the squares of deviation from the mean of x series is 136 and that of y series is 13. Sum of the product of the deviations of x and y series from their respective means is 122. Find the Pearson's coefficient of correlation.

If coefficient of correlation between two variables X and Y is 0.64, cov(X, Y)= 16" and "Var(X)= 9 , then the standard deviation of Y series is

A particle is executing S.H.M. If u_(1) and u_(2) are the velocitiesof the particle at distances x_(1) and x_(2) from the mean position respectively, then

If sum x_(1) = 16, sum y_(1) = 48 sum (x_(1) - 3) (y_(1) - 4) = 22 and n = 2 , find the cov (x,y).

If u = (x-3)/( 2) and v= ( y-2)/( 3), then cov(u,v) = k cov(x,y) . The value of k is

If (x , y) and (x ,y) are the coordinates of the same point referred to two sets of rectangular axes with the same origin and it u x+v y , where u and v are independent of xa n dy , becomes V X+U Y , show that u^2+v^2=U^2+V^2dot

IF cov(X, Y)= -8, Var(X)= 1.44" and "Var(Y)= 100 , then coefficient of correlation between X and Y is

Two particles are projected from a point at the same instant with velocities whose horizontal and vertical components are u_(1), v_(1) and u_(2), v_(2) respectively. Prove that the interval between their passing through the other common point of their path is (2(v_(1)u_(2) - v_(2) u_(1)))/(g (u_(1) + u_(2))