First Year ICS Statistics Chapter 7 Online MCQ Test (Random Variables)

Events with equal probabilities are called.

• Mutually exclusive events A
• Exhauative events B
• Eqauily likely events C
• Simple events D

The coins are tossed, the porbability of two tails is euql to.

• 1/2 A
• 1/4 B
• 3/4 C
• 1 D

Var (3x + 2)

• 3 Var(X) + 2 A
• 3 Var X B
• 9 var (x) + 2 C
• 9 var (x) D

 Var (3x+2)

• 3Var(x) + 2 A
•  9Var(x) +2 B
• Var (x) + 0  C
• 3Var (X) D

Variance of σ² is equal E to (Y²) - _______?

• E (y) A
• [E(y)]² B
• E(y²) C
• None of these D

• 4/10 A
• 2/10 B
• 1/10 C
• 0 D

For a constant K ,the variance of K.

• Zero A
• A^-2 B
• K C
• None of these D

The probability of an impossible event is.

• Positive A
• Zero B
• Negative C
• 1 D

E(x - μ) is equal to:

• E(x) A
• zero  B
• μ C
• X - μ D

The probability of getting two red balls with replacement from a bag containing 4 red, 3 white and 3 black balls is.

• 4/25 A
• 1/25 B
• 9/100 C
• 2/25 D

F (+∞) is always equal to:

• 0 A
• Two B
• One  C
• None of these D

If one event is unaffected by the outcome of another event, the two events are said to be

• Dependent A
• Independent B
• Mutually exclusive C
• Both b and c D

If mean = 25 and variance is also 25, then coefficient of variation is

• 100% A
• 25% B
• 20% C
• 10% D

F(y₁) ≤ F(y₂) if

• y₁= y₂ A
• Y₁>y₂ B
• y₁≤y₂ C
• y≥1/2 D

The probability of drawing a king of spade from a pack of 52 cards is.

• 1/4 A
• 1/13 B
• 1/26 C
• 1/52 D

If the random variable x denotes the number of heads of when three distinct coins are tossed k the X assumes values.

• 0,1,2,3 A
• 1,3,3,1 B
• 1,2,3 C
• 1,1,1,1 D

If x and y are independent random variables, E(xy)

• E(XY) A
• xE(y) B
• E(XY) C
• E(X) . E(Y) D