Find the answers

1. If for two variable x and y, the covariance. Variance of x and variance of y are 40, 16 and 256 respectively, what is the value of the correlation coefficient?

(a) 0.01    (b) 0.625    (c)   0.4   (d)  0.5

 
2. Following are the two normal equations obtained for deriving the regression line of y and x :

5a + 10b = 40; 10a + 25b = 95 the regression line of y on x is given by

(a) 2x + 3y = 5

(b) 2y + 3x = 5

(c) y = 2 + 3x

(d) y = 3 + 5x

3. If the regression line of y on x and of x on y are given by 2x+3y = —1 and 5x + 6y = —1 then the arithmetic means of x and y are given by

(a) (1, —1)   (b) (-1, 1)  (c)  (-1, —1)  (d) (2. 3)

4. Given the following equations: 2x — 3y = 10 and 3x + 4y = 15, which one is the regression equation of x on y?

(a) 1st equation (b) 2nd equation (c) both the equations (d) none