Target Exam

CUET

Subject

-- Applied Mathematics - Section B2

Chapter

Probability Distributions

Question:

A random variable X has the following probability distribution:

X 0 1 2 3 4
P(X) 2k k 4k 6k 3k

The mean of the distribution is :

Options:

$\frac{43}{16}$

$\frac{39}{8}$

$\frac{31}{24}$

$\frac{39}{16}$

Correct Answer:

$\frac{39}{16}$

Explanation:

The correct answer is Option (4) → $\frac{39}{16}$

Sum of all probabilities is 1.

$⇒2k+k+4k+6k+3k=1$

$⇒16k=1$

$⇒k=\frac{1}{16}$

Mean of the random variable X.

$E(X)=∑XP(X)$

$E(X)=(0×2k)+(1×k)+(2×4k)+(3×6k)+(4×3k)$

$=39k=39×\frac{1}{16}=\frac{39}{16}$