Target Exam

CUET

Subject

-- Applied Mathematics - Section B2

Chapter

Probability Distributions

Question:

The probability distribution of a discrete random variable is given as:

X

2

3

4

5

 P(X) 

 2k 

 5k 

 k 

 3k 

The value of E(X) is:

Options:

$\frac{15}{11}$

$\frac{38}{11}$

$\frac{38}{13}$

$\frac{15}{13}$

Correct Answer:

$\frac{38}{11}$

Explanation:

The correct answer is Option (2) → $\frac{38}{11}$

$2k + 5k + k + 3k = 11k = 1 \Rightarrow k = \frac{1}{11}$

$E(X) = 2(2k) + 3(5k) + 4(k) + 5(3k)$

$= 4k + 15k + 4k + 15k = 38k$

$= \frac{38}{11}$

$E(X) = \frac{38}{11}$