The probability distribution of a discrete random variable X is :
| X | 30 | 10 | -10 |
| P(X) | 1/5 | 3/10 | 1/2 |
Then E(X) is equal to :
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → 4
$E(X)=∑X.P(X)$
$=30.\frac{1}{5}+10.\frac{3}{10}+(-10).\frac{1}{2}$
$=6+3-5$
$=4$