MISCELLANEOUS EXERCISE - 3 -Choose the correct alternative.

1. Regression analysis is the theory of
a) Estimation          b) Prediction        c) Both a and b             d) Calculation

2. We can estimate the value of one variable with the help of other known variable only if they are
a) Correlated       b) Positively correlated       c) Negatively correlated        d) Uncorrelated

3. There are __________ types of regression equations.
a) 4        b) 2        c) 3      d) 1

4. In the regression equation of Y on X
a) X is independent and Y is dependent.
b) Y is independent and X is dependent.
c) Both X and Y are independent.
d) Both X and Y are dependent.

5. In the regression equation of X on Y
a) X is independent and Y is dependent.
b) Y is independent and X is dependent.
c) Both X and Y are independent.
d) Both X and Y are dependent.

6. bXY is __________
a) Regression coefficient of Y on X
b) Regression coefficient of X on Y
c) Correlation coefficient between X and Y
d) Covariance between X and Y

7. bYX is __________
a) Regression coefficient of Y on X
b) Regression coefficient of X on Y
c) Correlation coefficient between X and Y
d) Covariance between X and Y

8. ‘r’ is __________
a) Regression coefficient of Y on X
b) Regression coefficient of X on Y
c) Correlation coefficient between X and Y
d) Covariance between X and Y

9. bXY .bYX __________
a) v(x)      (b) σx      (c) r2        (d) (σy)2

10. If byx > 1 then bxy is __________
a) >1      (b) < 1     (c) > 0     (d) < 0

11. | bxy + byx| ≥ __________
a) |r|       (b) 2|r|      (c) r       (d) 2r

12. bxy and byx are __________
a) Independent of change of origin and scale
b) Independent of change of origin but not of scale
c) Independent of change of scale but not of origin
d. Affected by change of origin and scale

13. If u = x ac − and v = y bd − then byx =_____
a) d/c bvu   b) c/d bvu   c) a/b bvu      d) b/a bvu

14. If u = x ac − and v =ybd− then bxy =_____
a) d/c buv      b) c/d buv     c) a/b buv         d) b/a buv

15. Corr (x,x) = __________
a) 0     (b) 1       (c) −1      (d) can’t be found

16. Corr (x,y) = __________  
a) corr(x,x)       (b) corr(y,y)      c) corr(y,x)       (d) cov(y,x)

17. Corr [(x-a)/c), (y-b)/d]  = − corr(x,y) if,
a) c and d are opposite in sign
b) c and d are same in sign
c) a and b are opposite in sign
d) a and b are same in sign

18. Regression equation of X on Y is ____
a) y − y = byx (x − x )
b) x − x = bxy (y − y )
c) y − y = bxy (x − x )
d) x − x = byx (y − y )

19. Regression equation of Y on X is ______
a) y − y = byx (x − x )
b) x − x = bxy (y − y )
c) y − y = bxy (x − x )
d) x − x = byx (y − y )

20. byx = __________
a) r  σx/σy
b) r σy/σx
c) 1/r σy/σx
d) 1/r σx/σy

21. bxy = __________
a) r  σx/σy
b) r σy/σx
c) 1/r σy/σx
d) 1/r σx/σy

22. Cov (x,y) =__________
a) ∑( x- x)  − (y – y ) 
b) [∑(x – x) − (y – y)]/n
c) ∑xy/n − x y
d) b and c both

23. If bxy < 0 and byx < 0 then ‘r’ is __________
a) > 0     (b) < 0    (c) >1     (d) not found

24. If equations of regression lines are 3x + 2y − 26 = 0 and 6x + y − 31 = 0 then means of x and y are __________
a) (7,4)     b) (4,7)     c) (2,9)     d) (−4,7)