The probability distribution of a discrete random variable X is g… - Vidyadip

MCQ

The probability distribution of a discrete random variable X is given below:

$\text{X}:$	$1$	$2$	$3$	$4$
$\text{P}(\text{X}):$	$\frac{1}{10}$	$\frac{1}{5}$	$\frac{3}{10}$	$\frac{2}{5}$

The value of E(X²) is:

A
3
B
5
C
7
D
10

✓

Answer

10

Solution:

$\text{X}$	$1$	$2$	$3$	$4$
$\text{P}(\text{X})$	$\frac{1}{10}$	$\frac{1}{5}$	$\frac{3}{10}$	$\frac{2}{5}$
$\text{X}^2\text{P(X)}$	$\frac{1}{10}$	$\frac{4}{5}$	$\frac{27}{10}$	$\frac{32}{5}$	$\text{E}(\text{X}^2)=10$

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