Test: Mean And Variance Of A Random Variable

Question 1

In a series of 2 n observations, half of them equal ‘a’ and remaining half equal – a. If the standard deviation of the observations is 2, then | a | equals ……

Accepted Answer

2

Answer

&radic;2/n

Answer

1/n

Answer

&radic;2

Question 2

Let X be a random variable whose possible values x₁, x₂, x₃, …, x_n occur with probabilities p₁, p₂, p₃,…, p_n, respectively. The mean of X, denoted by

Accepted Answer

Answer

Answer

Answer

Question 3

The number of adults living in homes on a randomly selected city block is described by the following probability distribution.

What is the probability that 4 or more adults reside at a randomly selected home?

Accepted Answer

.10

Answer

.50

Answer

.25

Answer

.15

Question 4

Two dice are thrown simultaneously. If X denotes the number of sixes, then the expectation of X is:

Accepted Answer

1/3

Answer

1/2

Answer

1/4

Answer

1/6

Question 5

Let X be a random variable whose possible values x₁, x₂, x₃, …, x_n occur with probabilities p₁, p₂, p₃, …, p_n, respectively. Also, μ be the mean of X. The variance of X, denoted by Var(X), is defined as

Accepted Answer

Answer

Answer

Answer

Question 6

The variance of the number obtained on a throw of an unbiased dice is:

Accepted Answer

35/12

Answer

0

Answer

91/36

Answer

1

Question 7

The mean number of tails in three tosses of a fair coin is:

Accepted Answer

3/2

Answer

1/6

Answer

6

Answer

3

Question 8

A class has 10 students whose ages are 15, 14, 16, 17, 19, 20, 16, 18, 20, and 20 years. One student is selected in such a manner that each has the same chance of being chosen and the age X of the selected student is recorded. The standard deviation of X is:

Accepted Answer

2.11

Answer

17.5

Answer

4.45

Answer

4.41

Question 9

Let X be a random variable whose possible values x₁, x₂, x₃, …, x_n occur with probabilities p₁, p₂, p₃,…, p_n, respectively. Also, E(X) is the expectation of X, then E(X²) - [E(X)]² is known as

Accepted Answer

Variance

Answer

Standard deviation

Answer

Mean x variance

Answer

Mean

Question 10

In a meeting, 60% of the members favour and 40% oppose a certain proposal. A member is selected at random and we take X = 0 if he opposed, and X = 1 if he is in favour. Find E(X) and Var(X).

Accepted Answer

0.6 and 0.24

Answer

0.6 and 0

Answer

0.6 and 0.44

Answer

0.4 and 0.24

Mean And Variance Of A Random Variable - Free MCQ Practice Test with solutions,

MCQ Practice Test & Solutions: Test: Mean And Variance Of A Random Variable (10 Questions)

In a series of 2 n observations, half of them equal ‘a’ and remaining half equal – a. If the standard deviation of the observations is 2, then | a | equals ……

Let X be a random variable whose possible values x₁, x₂, x₃, …, x_n occur with probabilities p₁, p₂, p₃,…, p_n, respectively. The mean of X, denoted by

The number of adults living in homes on a randomly selected city block is described by the following probability distribution.
What is the probability that 4 or more adults reside at a randomly selected home?

Two dice are thrown simultaneously. If X denotes the number of sixes, then the expectation of X is:

Let X be a random variable whose possible values x₁, x₂, x₃, …, x_n occur with probabilities p₁, p₂, p₃, …, p_n, respectively. Also, μ be the mean of X. The variance of X, denoted by Var(X), is defined as

The variance of the number obtained on a throw of an unbiased dice is:

The mean number of tails in three tosses of a fair coin is:

A class has 10 students whose ages are 15, 14, 16, 17, 19, 20, 16, 18, 20, and 20 years. One student is selected in such a manner that each has the same chance of being chosen and the age X of the selected student is recorded. The standard deviation of X is:

Let X be a random variable whose possible values x₁, x₂, x₃, …, x_n occur with probabilities p₁, p₂, p₃,…, p_n, respectively. Also, E(X) is the expectation of X, then E(X²) - [E(X)]² is known as

In a meeting, 60% of the members favour and 40% oppose a certain proposal. A member is selected at random and we take X = 0 if he opposed, and X = 1 if he is in favour. Find E(X) and Var(X).

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Mean And Variance Of A Random Variable - Free MCQ Practice Test with solutions,

MCQ Practice Test & Solutions: Test: Mean And Variance Of A Random Variable (10 Questions)

In a series of 2 n observations, half of them equal ‘a’ and remaining half equal – a. If the standard deviation of the observations is 2, then | a | equals ……​

Let X be a random variable whose possible values x1, x2, x3, …, xn occur with probabilities p1, p2, p3,…, pn, respectively. The mean of X, denoted by

The number of adults living in homes on a randomly selected city block is described by the following probability distribution.What is the probability that 4 or more adults reside at a randomly selected home?​

Two dice are thrown simultaneously. If X denotes the number of sixes, then the expectation of X is:​

Let X be a random variable whose possible values x1, x2, x3, …, xn occur with probabilities p1, p2, p3, …, pn, respectively. Also, μ be the mean of X. The variance of X, denoted by Var(X), is defined as

The variance of the number obtained on a throw of an unbiased dice is:​

The mean number of tails in three tosses of a fair coin is:​

A class has 10 students whose ages are 15, 14, 16, 17, 19, 20, 16, 18, 20, and 20 years. One student is selected in such a manner that each has the same chance of being chosen and the age X of the selected student is recorded. The standard deviation of X is:​

Let X be a random variable whose possible values x1, x2, x3, …, xn occur with probabilities p1, p2, p3,…, pn, respectively. Also, E(X) is the expectation of X, then ​E(X2) - [E(X)]2 is known as

In a meeting, 60% of the members favour and 40% oppose a certain proposal. A member is selected at random and we take X = 0 if he opposed, and X = 1 if he is in favour. Find E(X) and Var(X).​

Chapter-wise Tests for JEE Main & Advanced

Chapter-wise Tests for JEE Main & Advanced

Top Courses for JEE

About this JEE Practice Test

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In a series of 2 n observations, half of them equal ‘a’ and remaining half equal – a. If the standard deviation of the observations is 2, then | a | equals ……

Let X be a random variable whose possible values x₁, x₂, x₃, …, x_n occur with probabilities p₁, p₂, p₃,…, p_n, respectively. The mean of X, denoted by

The number of adults living in homes on a randomly selected city block is described by the following probability distribution.
What is the probability that 4 or more adults reside at a randomly selected home?

Two dice are thrown simultaneously. If X denotes the number of sixes, then the expectation of X is:

Let X be a random variable whose possible values x₁, x₂, x₃, …, x_n occur with probabilities p₁, p₂, p₃, …, p_n, respectively. Also, μ be the mean of X. The variance of X, denoted by Var(X), is defined as

The variance of the number obtained on a throw of an unbiased dice is:

The mean number of tails in three tosses of a fair coin is:

A class has 10 students whose ages are 15, 14, 16, 17, 19, 20, 16, 18, 20, and 20 years. One student is selected in such a manner that each has the same chance of being chosen and the age X of the selected student is recorded. The standard deviation of X is:

Let X be a random variable whose possible values x₁, x₂, x₃, …, x_n occur with probabilities p₁, p₂, p₃,…, p_n, respectively. Also, E(X) is the expectation of X, then E(X²) - [E(X)]² is known as

In a meeting, 60% of the members favour and 40% oppose a certain proposal. A member is selected at random and we take X = 0 if he opposed, and X = 1 if he is in favour. Find E(X) and Var(X).