Home
Class 12
MATHS
If m and sigma^(2) are the mean and vari...

If `m and sigma^(2)` are the mean and variance of the random variable X, whose distribution is given by:
`{:(X=x:,0,1,2,3),(P(X=x):,(1)/(3),(1)/(2),0,(1)/(6)):}`

A

`m=sigma^(2)=2`

B

`m=1,sigma^(2)=2`

C

`m=sigma^(2)=1`

D

`m=2,sigma^(2)=1`

Text Solution

AI Generated Solution

The correct Answer is:
To solve the problem, we need to find the mean (m) and variance (σ²) of the random variable X given its probability distribution. The distribution is as follows: - P(X = 0) = 1/3 - P(X = 1) = 1/2 - P(X = 2) = 0 - P(X = 3) = 1/6 ### Step 1: Calculate the Mean (m) The mean (expected value) of a discrete random variable is calculated using the formula: \[ m = E(X) = \sum (x_i \cdot P(X = x_i)) \] Substituting the values from the distribution: \[ m = (0 \cdot \frac{1}{3}) + (1 \cdot \frac{1}{2}) + (2 \cdot 0) + (3 \cdot \frac{1}{6}) \] Calculating each term: - \(0 \cdot \frac{1}{3} = 0\) - \(1 \cdot \frac{1}{2} = \frac{1}{2}\) - \(2 \cdot 0 = 0\) - \(3 \cdot \frac{1}{6} = \frac{3}{6} = \frac{1}{2}\) Now, summing these values: \[ m = 0 + \frac{1}{2} + 0 + \frac{1}{2} = 1 \] Thus, the mean \(m = 1\). ### Step 2: Calculate the Variance (σ²) To find the variance, we first need to calculate \(E(X^2)\): \[ E(X^2) = \sum (x_i^2 \cdot P(X = x_i)) \] Substituting the values: \[ E(X^2) = (0^2 \cdot \frac{1}{3}) + (1^2 \cdot \frac{1}{2}) + (2^2 \cdot 0) + (3^2 \cdot \frac{1}{6}) \] Calculating each term: - \(0^2 \cdot \frac{1}{3} = 0\) - \(1^2 \cdot \frac{1}{2} = \frac{1}{2}\) - \(2^2 \cdot 0 = 0\) - \(3^2 \cdot \frac{1}{6} = \frac{9}{6} = \frac{3}{2}\) Now, summing these values: \[ E(X^2) = 0 + \frac{1}{2} + 0 + \frac{3}{2} = 2 \] Now, we can calculate the variance using the formula: \[ \sigma^2 = E(X^2) - m^2 \] Substituting the values we found: \[ \sigma^2 = 2 - (1)^2 = 2 - 1 = 1 \] Thus, the variance \(σ² = 1\). ### Final Result The mean \(m\) is 1 and the variance \(σ²\) is also 1. ### Summary - Mean \(m = 1\) - Variance \(σ² = 1\)
Promotional Banner

Similar Questions

Explore conceptually related problems

Find the mean and variance of the random variable X whose distribution is

Find the mean and variance of the random variable X which follows the following distribution.

If the probability of a random variable X is a given below : {:(X=x:,-2,-1,0,1,2,3),(P(X=x):,(1)/(10),k,(1)/(5),2k,(3)/(10),k):} Then the value of k, is :

The mean and variance of a random variable X having a binomial distribution are 4 and 2 respectively. The P(X=1) is

A random variable X has the following distribution {:(x:,1,2,3,4),(P(X=x):,k^(2),3k^(2),5k^(2),7k^(2)):} The value of k is

X is a random variable with distribution given below {:(x:,0,1,2,3),(P(X=x):,k,3k,3k,k):} The value of k and its variance are

The mean and variance of a random variable X having binomial distribution are 4 and 2 respectively. Then P(x gt 6)=

If the mean and variance of a binomial variable X are 2 and 1 respectively. Find P(X >1) .

If a random variable X has a Poisson distribution with parameter 1//2 , then P(X=2)=

The probability distribution of a random variable X is given by. {:(X=x:,0,1,2,3,4),(P(X=x):,0.4,0.3,0.1,0.1,0.1):} The variance of X, is