Practicing Success

Target Exam

CUET

Subject

-- Mathematics - Section A

Chapter

Probability

Question:

The random variable X has a probability distribution

\(P(X=x)=\begin{Bmatrix}5k, & x=1\\2k, & x=1\\3k, & x=2\\0, & otherwise\end{Bmatrix}\)

Then, the value of E(X) is:

Options:

0.8

0.4

1

0.5

Correct Answer:

1

Explanation:

x

0

1

2

E(x)

5k

2k

3k

Since x is random variable

its sum of probabilities is equal to 1

$\sum_0^4E(x)=1$

$E(x=0)+E(x=1)+E(x=2)=1$

$5k+2k+3k=1$

$10k = 1$

$k=\frac{1}{10}$