Question

Mark the correct alternative in the following question:
For the following probability distribution:

X:	−4	−3	−2	−1	0
P(X):	0.1	0.2	0.3	0.2	0.2

The value of E(X) is

 

 

Options

• 0  

• −1 

• −2 

• −1.8

Answer 1

The probability distribution of X is given below:
 

X:	−4	−3	−2	−1	0
P(X):	0.1	0.2	0.3	0.2	0.2

\[E\left( X \right) = \left( - 4 \right) \times 0 . 1 + \left( - 3 \right) \times 0 . 2 + \left( - 2 \right) \times 0 . 3 + \left( - 1 \right) \times 0 . 2 + 0 \times 0 . 2\]
\[ = - 0 . 4 - 0 . 6 - 0 . 6 - 0 . 2\]
\[ = - 1 . 8\]