If cov(x,y)= -1.55, var (x) = 1.55, var (y)= 1.55, then ρ(x,y) =
1
-1
0
None of these.
The lines of regressions make angles 300 and 600 with the positive direction of the x-axis . Then the coefficient of correlation between x and y is
√3
1/√3
The coefficient of correlation is independent of
Change of origin only
Change of scale only
Change of origin and scale
The regression lines of y on x is 2x-3y+5 =0. The regression coefficient of y on x is
-2/3
3/2
2/3
If x and y are independent then cov (x,y)= ___________
0.5
In the case of perfect correlation between x and y, the number of regression lines is
2
More than 2
The regression coefficients are -0.8 and -0.8. The coefficient of correlation is
0.64
0.8
-0.8
The square of the correlation coefficient is
The square of the regression coefficient
The square root of the regression coefficient
The product of the regression coefficient
Always unity.
The Karl Pearson's coefficient of correlation
Cannot be greater than-1
Lies in the closed interval [-1,1]
lies in the open interval (-1,1)
If r=0, then the regression lines are.
Non-zero
Coincident
Perpendicular
Not perpendicular.
