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).

For a bivariate date, you are given following information: sum x = 125 , sum x^(2) = 1650 , sum y = 100 , sum y^(2) = 1500 , sum xy= 50 , n= 25 Find line of regression.

If xy + yz + zx = 1 then sum (x + y)/(1 - xy)=

If sum_(i=1)^(7) i^(2)x_(i) = 1 and sum_(i=1)^(7)(i+1)^(2) x_(i) = 12 and sum_(i=1)^(7)(i+2)^(2)x_(i) = 123 then find the value of sum_(i=1)^(7)(i+3)^(2)x_(i)"____"

Calculate Kari Pearson's coefficient of correlation between the values of x and y for the following data : n = 10, sum x = 55, sum y = 40, sum x^(2) = 385, sum y^(2) = 192 and sum (x + y)^(2) = 947

If n= 10, sum_(i=1)^(10) x_(i) = 60 and sum_(i=1)^(10) x_(i)^(2) = 1000 then find s.d.

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 f(x+y)=f(x).f(y) and f(1)=4 .Find sum_(r=1)^n f(r)

If x + y = 1 , prove that sum_(r=0)^(n) r""^(n)C_(r) x^(r ) y^(n-r) = nx .

A path of length n is a sequence of points (x_(1),y_(1)) , (x_(2),y_(2)) ,…., (x_(n),y_(n)) with integer coordinates such that for all i between 1 and n-1 both inclusive, either x_(i+1)=x_(i)+1 and y_(i+1)=y_(i) (in which case we say the i^(th) step is rightward) or x_(i+1)=x_(i) and y_(i+1)=y_(i)+1 ( in which case we say that the i^(th) step is upward ). This path is said to start at (x_(1),y_(1)) and end at (x_(n),y_(n)) . Let P(a,b) , for a and b non-negative integers, denotes the number of paths that start at (0,0) and end at (a,b) . The sum P(43,4)+sum_(j=1)^(5)P(49-j,3) is equal to

Let x_(1) lt x_(2) lt x_(3) lt x_(4) lt x_(5) and y_(1) lt y_(2) lt y_(3) lt y_(4) lt y_(5) are in AP such that underset(I = 1)overset(5)(sum) x_(i) = underset(I = 1)overset(5)(sum) y_(i) = 25 and underset(I =1)overset(5)(II) x_(i) = underset(I = 1)overset(5)(II) y_(i) = 0 then |y_(5) - x_(5)| A. 5//2 B. 5 C. 10 D. 15