Question:

If 𝝈𝒚 ൌ 𝟒, byx = 0.48, r = 0.6, then is 𝝈𝒙

A.

5

B.

7

C.

9

D.

6.5

Answer» a. 5

Question:

If the relation between two variables x and y be 5x + 7y = 28 and median of y be 3, then the median of x is

A.

1.4

B.

– 4.2

C.

3

D.

13/7

Answer» a. 1.4

Question:

If A.M and the coefficient of variation of x are 6 and 50% respectively, then the variableof x is

A.

3

B.

6

C.

9

D.

11

Answer» c. 9

Question:

For two mutually exclusive events A and B if P(A) = 3/4 and P(B) = 1/6, then P(A or B) is

A.

11/12

B.

5/12

C.

7/8

D.

1/8

Answer» a. 11/12

Question:

If y = 3x + 30 and mean of x is 20, then the mean of y is

A.

90

B.

80

C.

70

D.

100

Answer» a. 90

Question:

When Var (x) = 2.25, Var (y) = 1 and Cov (x, y) = 0.9, then correlation coefficient is

A.

0.45

B.

0.8

C.

0.6

D.

0.75

Answer» c. 0.6

Question:

A.M of 40 observations of a variable is 25 and S.D is 4. The sum of squares of allobservations is

A.

25640

B.

26540

C.

24560

D.

26450

Answer» a. 25640

Question:

The Standard Deviation for two observations is

A.

square of their difference.

B.

half of their absolute difference

C.

their absolute difference

D.

twice of their absolute difference

Answer» b. half of their absolute difference

Question:

For two mutually exclusive events A and B, if P(A) = 0.4 and P(B) = 0.3, then P (A or B) is

A.

0.6

B.

0.58

C.

0.7

D.

0.75

Answer» c. 0.7

Question:

If the Harmonic Mean of 2, a, 8 be 24/7, the value of a is 17

A.

4

B.

6

C.

12

D.

9

Answer» a. 4